Agronomy rawm

LECTURE NOTE ON
Agron 6.10
RAINFED AGRICULTURE AND WATERSHED MANAGEMENT
6TH
SEMESTER
B.Sc. (Tech) Agri.
DR. K. D. MEVADA
Associate Professor
Department of Agronomy
B.A. College of Agriculture
Anand Agricultural University
Anand
DR. T.C.POONIA
Assistant Professor
College of Agriculture
Junagadh Agricultural University
Amreli
PIYUSH SARAS
Assistant Professor
C.P. Patel College of Agriculture
Sardarkrushinagar Dantiwada
Agricultural University
Sardarkrushinagar
S.P. DESHMUKH
Assistant Professor
College of Agriculture
Navsari Agricultural University
Bharuch

Course No. : Agron 6.10
Title of Course: Rainfed Agriculture and Watershed Management
Credit: 1+1 = 2
C O N T E N T
(THEORY)
Unit
Lecture
No.
Sub topics
Page
No.
I
Rainfed Agriculture
1 Introduction, types, History of Rainfed
Agriculture in India
1-8
2 Problems and prospects of Rainfed Agriculture
in India
9-14
3 Soil and climatic conditions prevalent in
rainfed areas
15-31
II
Soil and Water
Conservation Techniques
4 Soil erosion; water and wind, Soil and water
conservation techniques
32-40
III
Drought
5 Types, effect of water deficit on physio-
morphological characteristics of the plants
41-45
6 Crop adaptation and mitigation to drought 46-48
IV
Water Harvesting
7 Importance, its techniques, efficient utilization
of water through soil and crop management
practices
49-62
V
Management of Crops in
Rainfed Areas
8 Management of crops in rainfed areas 63-71
VI
Contingent Crop Planning
for Aberrant Weather
Conditions
9 Contingent crop planning for aberrant weather
conditions
72-77
VII
Watershed Management
10 History of watershed in India, Concept,
objective, principles and components and
Factors affecting Watershed Management
78-95
Glossary and
Abbreviations
- - i-x

Rainfed Agriculture: Introduction, Types and History of Rainfed Agriculture in India
Rainfed Agriculture and Watershed Management: Mevada K. D., Poonia T. C, Saras Piyush and Deshmukh S.P. Page 1
1
Rainfed Agriculture: Introduction, Types and
History of Rainfed Agriculture in India
1.1 Introduction
Even after the utilization of all our water resources for irrigation, about half of the
cultivated area will remain rainfed. As there is hardly any scope for increasing the area under
cultivation, it is really a colossal task for meeting the future food needs. It is against this
background that the role of dryland agriculture gained importance. Agriculture is the single
largest livelihood sources in India with nearly two thirds of people depend on it. Rainfed
agriculture is as old as agriculture itself. Growing of crops entirely under rainfed conditions is
known as dryland agriculture.
Very often, the words dry farming, dryland agriculture and rainfed agriculture are used
synonymously to indicate similar farming situation. Clearly, the two exclude irrigations.
Depending on the amount of rainfall received, it can be grouped into three categories:
Types of Dryland/Rainfed Agriculture
1.2 Definitions
a) Dry farming: is cultivation of crops in regions with annual rainfall less than 750 mm.
Crop failures is most common due to prolonged dry spells during the crop period. These are
arid regions with a growing season (period of adequate soil moisture) less than 75 days.
Moisture conservation practices are necessary for crop production.
b) Dryland farming: is cultivation of crops in regions with annual rainfall more than 750
mm. In spite of prolonged dry spells crop failure is relatively less frequent. These are semi-
arid tracts with a growing period between 75 and 120 days. Moisture conservation practices
are necessary for crop production. However, adequate drainage is required especially for
vertisols or black soils.
C) Rainfed farming: is crop production in regions with annual rainfall more than 1150 mm.
Crops are not subjected to soil moisture stress during the crop period. Emphasis is often on
disposal of excess water. These are humid regions with growing period more than 120 days.
In dry farming and dryland farming, emphasis is on soil and water conservation, sustainable
crop yields and limited fertilizer use according to soil moisture availability. In rainfed
agriculture, emphasis is on disposal of excess water, maximum crop yield, high levels of
inputs and control of water erosion.
Sr.
No.
Particular Dry
Farming
Dryland
Farming
Rainfed
farming
1 Rainfall/annum
(mm)
< 750 750 – 1150 > 1150
2 Moisture availability Acute shortage Shortage Enough
3 Crop growing season < 75 days 75 – 120 days > 120 days
4 Growing region Arid Semi-arid Humid
5 Cropping systems Single crop/
intercropping
Single crop/
intercropping
Inter/ Multi-
cropping

6 Dry spells Most common Less frequent No occurrence
7 Crop failure More frequent Less frequent Rare
8 Constraints Wind erosion Wind erosion/ water
erosion
Water erosion
9 Measures Required Moisture
conservation
practices
Moisture
conservation
practices
& drainage for
vertisols
Proper drainage
required
United Nations Economic and Social Commission (UNESC) for Asia and the Pacific
distinguished dryland agriculture mainly into two categories: dryland and rainfed farming.
The distinguishing features of these two types of farming are given below
1.3 Dryland farming v/s Rainfed farming
Constituent Dryland farming Rainfed farming
Rainfall (mm) <750 >750
Moisture availability to the
crop
Shortage Enough
Growing season (days) <200 >200
Growing regions Arid and semiarid as well as
uplands of sub-humid and
humid regions
Humid and sub-humid
regions
Cropping system Single crop or intercropping Intercropping or double
cropping
Constraints Wind and water erosion Water erosion
1.4 The Concept:
The concept of rainfed agriculture (farming) under which both dry farming and dryland
farming (dryland agriculture) is included has been changed. Dry farming was the earlier
concept for which amount of rainfall (less than 500 mm annually) remained the deciding
factor for more than 60 years.
In modem concept, dryland areas are those where the balance of moisture is always
deficit side. In other words, annual evapotranspiration exceeds precipitation. In dryland
agriculture, there is no consideration of amount of rainfall. It may appear quite strange to a
layman that even those areas which receive 1100 mm or more rainfall annually fall in the
category of dryland agriculture under this concept. To be more specific, the average annual
rainfall of Varanasi is around 1100 mm and the annual potential evapotranspiration is 1500
mm. Thus the average moisture deficit so created comes to 400 mm. This deficit in moisture
is bound to affect the crop production under dryland situation, ultimately resulting into total
or partial failure of crops. Accordingly, production is either low or extremely uncertain
and unstable which are the real problems of dryland in India.

Success of crop production in these areas depends on the amount and distribution of
rainfall, as these influences the stored soil moisture and moisture used by crops. Amount of
water used by crop and stored in soil is governed by water balance equation:
ET = P - (R + S)
When balance of the equation shifts towards right, precipitation (P) is higher than ET, so
that there may be water logging or it may even lead to runoff (R) and flooding. On the other
hand, if the balance shifts to left, ET becomes higher than precipitation, resulting in drought.
Taking the country as a whole, as per meteorological report, severe drought in large area is
experienced once in 50 years and partial drought once in five years while floods are expected
every year in one or other part of the country, especially during rainy season. In fact, the
balance of the equation is controlled by weather, season, crops and cropping pattern.
Present Status
 Growing of crops entirely under rainfed conditions is known as dryland agriculture.
 India has about 108 m ha as rainfed area/dryland agriculture of total 143 m ha (67 %)
 Dry farming contribute in total food grains production: 44 %
 Area under oilseeds (groundnut, rapeseed, mustard and soybean): 80 %
 Nearly 67 M ha of rainfed area falls in the mean annual precipitation range of 500 –
1500 mm.
 Average annual rainfall of the country is 1200 mm amounting to 400 M ha-m of
rainwater over the country's geographical area (329 M ha).
 However, distribution across the
country varies from less than
100 mm in extreme arid areas of
western Rajasthan to more than
3600 mm in NE states and 1100
mm from East Coast to 2500-
3000 mm in the West Coast.
 Broad area of summer monsoon
activity extends from 30o
N to
30o
S and from 30o
W to 16.5o
E. Detailed information on
rainfall and monsoonal pattern
in India has been summarized
below.
Rainfall pattern in India
Season/Period M ha-m Per cent
Winter (Jan-Feb) 12 3
Pre-monsoon (March-May) 52 13
S – W monsoon (June – Sept.) 296 74
N – E monsoon (Oct-Dec) 40 10
Total for the Year 400 100

 India ranks first in rainfed agriculture globally in both area (86 M ha) and the value of
produce.
 Rainfed regions in India contribute substantially toward food grain production including
44% of rice, 87% of coarse cereals (sorghum (Sorghum bicolor L.), pearl millet
(Pennisetum glaucum L.), maize (Zea mays L.), and 85% of food legumes, 72% of
oilseeds, 65% of cotton, and 90% of minor millets (Table 1.2).
 Rainfed agriculture, with nearly 58 per cent of the cultivated area, contributes 40 per
cent of the country's food production.
 Even after full irrigation potential of the country is realized, half of the cultivated area
will continue to be under rainfed fanning.
 Hence, it is necessary to increase the productivity of major rainfed crops to meet the
ever-increasing demand for food and fiber.
 During the past 25 years, there occurred significant changes in the area and yield of
important crops of rainfed areas.
 Area under coarse cereals decreased by about 10.7 M ha and most of this was under
sorghum.
 Area under oilseeds increased by 9.2 M ha and most of this increase was due to
irrigated rapeseed and mustard and soybean.
 Total area under pulses and cotton remained constant but more of cotton became
irrigated and shifts in the area occurred from one agro-ecological region to others.
Area under chickpea in northern belt decreased but increase in central belt. This
change occurred due to increase in area under rice-wheat cropping system which
displaced chickpea and also pearl millet to a great extent and maize to a small extent.
Table 1.2: Area sown under various rainfed crops and percentage of rainfed area
Crop Area sown (M ha) Rainfed area (%)
Rice 45.5 42
Coarse cereals 27.5 85
Sorghum 7.5 91
Pearl millet 8.7 91
Maize 8.2 75
Pulses 22.1 83
Pigeonpea 3.4 96
Bengalgram (Chickpea) 7.9 67
Oilseeds 27.6 70
Groundnut 6.2 79
Rapeseed and mustard 6.3 27
Soybean 9.5 99
Sunflower 1.8 69
Cotton 9.4 65
 Of these 25 districts, covering 18 M ha of net area sown with 10 per cent of irrigation,
receives 375-750 mm rainfall annually spread over central Rajasthan, Saurashtra
region of Gujarat and rain shadow region of Western Ghats in Maharashtra and
Karnataka.

Basic Facts:
 India is home to 18% of world’s population, 15% of the world livestock, 4.2% of fresh water
resources, 1% of forests, and 0.5% of pasture land, but only has 2.3% of the geographical
area.
 India is home to 25% of the world’s hungry population of world. 1 billion along with an
estimated 43% of children malnourished under the age of five.
 The net sown area in India has remained constant for several years at 141 M ha, but the
human and livestock populations have been steadily increasing. Though the Indian
population increased from 361 million in 1951 to 1360 million in 2019, the food-grain
production has more than quadrupled, but the yield gains are largely from the irrigated agro-
eco systems.
 Notwithstanding the increase in average productivity from 0.6 t / ha in the 1980s to 1.1 t/ ha
at the present time, large yield gaps exist for rainfed crops in the semiarid regions.
 Even after realizing the full irrigation potential, nearly 40% of the net sown area of 142 M ha
will remain totally rainfed.
 The per capita availability of land has fallen drastically from 0.37 ha in 1951 to about 0.19
ha in 2001; and it is projected to decline further to 0.09 ha by 2050. According to the World
Bank collection of development indicators arable land (hectares per person) in India was
reported at 0.11813 in 2016.
Area Under Irrigated and rainfed
conditions in India
Class Area
(m
ha)
%age of
total
Arable
Total
Arable
143.8 100
Dryland 34.5 24.0
Rainfed 65.5* 45.5
Irrigated 43.8 30.5
*Includes Flood-prone area of 15
m/ha
Per Capita Land Availability
Year Cropped
Area
(m.ha)
Total
Population
(m)
Av. Land
per capita
(ha)
1951 13189 361.1 0.37
1971 165.79 548.2 0.30
1991 185.74 846.3 0.22
2001 190.76 1027 0.19
2050 200.00 1600 0.09
Arable-land-hectares-per-person (tredingeconomics.com)
Principles of Agronomy, Reddy & Reddy, 2016 Food security and SRI,
Pradhan et al., 2019
 Increasing productivity of rainfed cropping systems is of critical importance to meet the food
demands of an ever-increasing population in India.
 The potential productivity of maize (Z. mays) in high rainfall regions under rainfed condition
are 8.0 t/ha vis-a-vis the national average yield of 2.1 t/ ha, indicating an unabridged yield
gap of 6 t/ ha. Large yield gaps exist in other crops as well which are primarily grown under
rainfed conditions.
 Recommended management practices (RMPs) such as improved cultivars, site specific
nutrient management (precision agriculture), and water harvesting and recycling can
potentially increase the yields in several crops up to 6 t/ ha, indicating the large realizable
potential under rainfed conditions.
 There are many districts in India where the actual yields are much lower than the national
average, and there is enormous potential for improvement.

 According to the present concept, there are 128 districts in the country which face the
problems of dryland.
 Twelve districts have irrigation covering 30-50 per cent of the cropped area and do not
pose serious problems.
 Remaining 91 districts covering mainly Madhya Pradesh, Gujarat, Maharashtra, Andhra
Pradesh. Karnataka, Uttar Pradesh parts of Haryana, Tamil Nadu etc. represent typical
dryland area. Total net sown area in these districts is estimated to be 42 M ha of which
5 M ha are irrigated. Rainfall in these districts varies from 375 to 1125 mm. Therefore,
more and more efforts are to be made for enhanced and stable production in these areas
so that the recurring droughts do not stand in the way of meeting the growing food
demands.
History of Dryland/Rainfed Agriculture:
 First systematic scientific approach to tackle the problems of dry farming areas was
initiated by Tamhane in 1923 on a small plot at Manjri Farm near Pune and the work
passed on to kanitkar in 1926.
 A comprehensive scheme of research was drawn up by Kanitkar with financial
support from the ICAR. Realizing the importance, the 1CAR launched a
comprehensive project on dryland farming at five centers: Sholapur and Bijapur in
1933, Hagari and Raichur in 1934 and Rohtak in 1935.
 A decade of work up to 1943-44 mainly on rainfall analysis, physico-chemical
properties of soils, physiological studies on millets and on agronomic aspects resulted
in a series of dry farming practices commonly known as the Bombay dry farming
practices, Hyderabad dry farming practices and Madras dry farming practices.
 These practices stressed the need for contour bunding, deep ploughing, and
application of FYM, low seed rate with wide spacing, mixed cropping and crop
rotation. These recommendations could not motivate the farmers to adopt them as the
yield advantage was about 15-20 per cent over a base yield of 200-400 kg/ ha.
 By the mid-1950s, importance of soil management (soil and moisture conservation)
was realized for improving the productivity of dryland and the ICAR established eight
Soil Conservation Research Centers in 1954. However, yield improvement was not
more than 15-20 per cent over the basic yield of 200-400 kg/ha.
 Importance of short duration cultivars maturing within adequate soil moisture
available period (crop growing period) was recognized during 1960s.
 The place of high yielding varieties and hybrids for yield advantage in dryland
agriculture was realized in mid-1960s.
 With the establishment of All India Coordinated Research Project for Dryland
Agriculture (AICRPDA) in 1970, emphasis was shifted to multi-disciplinary approach
to tackle the problem from several angles.
 Similar efforts were initiated at ICR1SAT, Hyderabad in 1972.
 The ICAR selected 25 dryland agricultural centers all over the country on the basis of
the moisture deficit, soil type and rainfall characteristics as indicated below :

1. Agra (Uttar Pradesh) 2. Akola (Maharashtra)
3. Anantapur (Anadhra Pradesh) 4. Arjia (Rajasthan)
5. Ballowal Saunkhri (Punjab) 6. Bengaluru (Karnataka)
7. Bijapur (Karnataka) 8. Biswanath Chariali (Assam)
9. Chianki (Jarkhand) 10. Faizabad (Uttar Pradesh)
11. Hisar (Haryana) 12. Indore (Madhya Pradesh)
13. Jagdalpur (Chattisgarh) 14. Kovilpatti (Tamil Nadu)
15. Parbhani (Maharashtra) 16. Phulbani (Odisha)
17. Rajkot (Gujarat) 18. Rakhdhiansar (J & K)
19. Rewa (Madhay Pradesh) 20. Sardarkrushinagar (Gujarat)
21. Solapur (Maharashtra) 22. Varanasi (Uttar Pradesh)
23. Bellary (Karnataka) 24. Jhansi (Uttar Pradesh)
25. Jodhpur (Rajasthan)
The chronology of major events in dryland agricultural research in India is as follows:
1880 The First Famine Commission was appointed by the then British Empire to suggest
ways and means to offset the adverse effects of recurring droughts, which country
faced from 1860 onwards. An important recommendation of the commission was to
set up protective irrigation project.
1920 The Royal Commission on Agriculture stressed the need for scarcity tract
development.
1923 Imperial Council of Agricultural Research sanctioned six schemes and established the
first Dryland Research Station at Manjari (Pune) by Tamhane.
1933 Bombay Dry Farming Research Schemes at Bijapur and Sholapur the centers of
famine tract.
1934 The Madras Dry Fanning Research Scheme at Hagari (near Bellary) and the
Hyderabad Dry Farming Research Scheme at Raichur.
1935 The Punjab Dry Farming Research Scheme at Rohtak (Punjab).
1942 Bombay Land Development act passed.
1944 Monograph on dry fanning in India by NV Kanitkar (Bombay, Hyderabad and
Madras Dry Farming Practices)
1953 Establishing Central Soil Conservation Board.
1954 The Central Soil and Water Conservation Research and Training Institute at
Dehradun.
1954 Soil Conservation Research, Demonstration and Training Center, Ootacamund.
1954 Soil Conservation Research, Demonstration and Training Center, Bellary.
1954 Soil Conservation Research, Demonstration and Training Center, Kota.
1955 Soil Conservation Research, Demonstration and Training Center, Vasad.
1957 Soil Conservation Research, Demonstration and Training Center, Agra.
1957 Soil Conservation Research, Demonstration and Training Center, Chandigarh.
1959 Central Arid Zone Research Institute (CAZRI) was established at Jodhpur to tackle
the problems of arid agro-ecosystem.
1962 Soil Conservation Research. Demonstration and Training Center. Ibrahimpatnam.
1962 Launching of Soil Conservation in the Catchments of River Valley Projects.

1970 All India Coordinated Research Project for Dryland Agriculture (AICRPDA) in 23
locations (now 25) with the support from Canadian International Development
Agency through an instrument of bilateral collaboration signed between the
Governments of India and Canada (up to 1987).
1972 The Consultative Group on International Agricultural Research (CGIAR) established
the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) at
Hyderabad
1976 Establishment of Dryland Operational Research, Projects.
1980 Integrated Watershed Management in the Catchment of Flood prone area
1983 Starting of 47 model watersheds under ICAR.
1984 Initiation of World Bank assisted Watershed Development Programs in four states
1985 The Central Research Institute for Dryland Agriculture (CRIDA) at Hyderabad
1985 National Wasteland Development Board (NWDB).
1986 Launching of NWDPRA programs by Government of India in 15 states
1989 Integrated Watershed Development Projects (IWDP) by National Watershed
Development Board (NWDB)
2006 National Rainfed Area Authority (NRAA).
The ICAR collaborated with Canadian dryland research (Indo-Canadian Dryland
Research, from 1970 to 1987. The 1CAR-1CR1SAT collaborative research programs
are working in areas of biological nitrogen fixation, agro-forestry, soil and moisture
conservation, economics of watershed technology and vegetative barriers in soil and
water conservation. The Indo-US collaboration started in 1980. Currently, CRIDA-US
collaborative research projects are working on fertilizer use efficiency, germplasm
enhancement, evaluation of legumes for high nitrogen fixation, crap simulation
modeling and implements for dryland agriculture.
Rainfed Agriculture Research in Gujarat
Agricultural Research Station, JAU, Targadia
Agricultural Research Station, AAU, Arnej
Major constraints and problems in these areas are:
1. Uncertain, erratic and uneven distribution of rainfall
2. Degradation of forests and natural tree cover
3. Low soil fertility and soil depth
4. Shortage of drinking water and assured irrigation for crops
5. Considerable area under wastelands
6. Cultivation of marginal lands due to population and animal pressure
7. Lack of infrastructure and facilities
8. Shortage of fuel wood and fodder
9. Continuance of traditional varieties and management practices
10. Improper management of community lands
x-x-x-x-x

Problems and prospects of Rainfed Agriculture in India
2
2.1 Problems or constraints for crop production in dry farming regions
Most of the cropping in the arid and semi-arid regions continues to be under rainfed
conditions. A majority of the farmers are small farmers with meager resources. The poor
resource base permits only low input subsistence farming with low and unstable crop yields.
The low productivity of agriculture in dry farming regions is due to the cumulative effect of
many constraints for crop production.
The problems can be broadly grouped in to
a) Climatic constraints
b) Soil constraints
c) Lack of suitable varieties
d) Traditional cultivation practices
e) Heavy weed infestation
f) Resource constraints
g) Technological constraints
f) Socio economic constraints
2.1.1 Climatic constraints
A) Rainfall characteristics: Among the different climatic parameters, rainfall is an
important factor influencing the crop production in dry regions
(i) Variable rainfall: Rainfall varies both in time and space dimension. Annual rainfall
varies greatly from year to year and naturally, its coefficient of variation is very high.
Generally, higher the rainfall less is the coefficient of variation. In other words, crop failures
due to uncertain rains are more frequent in regions with lesser rainfall. The average annual
rainfall of India is 1192 mm where as in Gujarat it is 816 mm. Based on the average annual
rainfall, the India can be divided into four zones. More than one third of total geographical
area in India receives rainfall less than 750 mm (Table. 2.1).
(ii) Intensity and distribution: In general, more than 50 per cent of total rainfall is usually
received in 3 to 5 rainy days. Such intensive rainfall results in substantial loss of water due to
surface runoff. This process also accelerates soil erosion. Distribution of rainfall during the
crop growing season is more important than total rainfall in dryland agriculture.
iii) Aberrations or variations in monsoon behavior
(a) Late onset of monsoon: If the onset of monsoon is delayed, crops/varieties recommended
to the region cannot be sown in time. Delayed sowing lead to uneconomical crop yields.
(b) Early withdrawal of monsoon: This situation is equally or more dangerous than late
onset of monsoon. Rainy season crops will be subjected to terminal stress leading to poor
yields. Similarly, post-rainy season crops fail due to inadequate available soil moisture,
especially during reproductive and maturity phases.
(c) Prolonged dry spells: Breaks of monsoon for 7-10 days may not be a serious concern.
Break between two consecutive rainfalls for more than 15 days duration especially at critical
stages for soil moisture stress, leads to reduction in yield. Drought due to break in monsoon
may adversely affect the crops in shallow soils than in deep soils. It also has ill-effect on crop
yield in tropical and sun-tropical regions.

High atmospheric temperature: Because of high atmospheric temperature, the atmospheric
demand for moisture increases causing high evapotranspiration losses resulting in moisture
stress.
B) Low relative humidity: Low relative humidity results in high ET losses causing moisture
stress whenever moisture is limiting.
D) Hot dry winds: Hot dry winds causes desiccation of leaves resulting in moisture
stress. High turbulent winds especially during summer months cause soil erosion
resulting in dust, storms and loss of fertile soil.
E) High atmospheric water demand: Due to high atmospheric water demand the
potential evapotranspiration (PET) exceed the precipitation during most part of the
year.
2.1.2 Soil Constraints
The different soil groups encountered in dryland areas are black soils, red soils and
alluvial soils. The constraints for crop production are different in different soil groups. The
predominant soil group is alluvial where the problems for crop production are not so acute as
in red and black soils. The different soil constraints for crop production are
a) Inadequate soil moisture availability: The moisture holding capacity of soils in dry
regions is low due to shallow depth especially in alfisols (red soils), low rainfall and low
organic matter content.
b) Poor organic matter content: The organic matter content in most of the soils under
dryland conditions is very low (< 1 %) due to high temperature and low addition of organic
manures. Poor organic matter content adversely affects soil physical properties related to
moisture storage.
c) Poor soil fertility: Due to low accumulation of organic matter and loss of fertile top soil-
by-soil erosion, the dry land soils are poor in fertility status. Most of the dry land soils are
deficient in nitrogen and zinc.
d) Soil deterioration due to erosion (wind, water): In India nearly 175 m.ha of land is
subjected to different land degradations, among them, the soil erosion is very predominant.
The erosion causes loss of top fertile soil leaving poor sub soil for crop cultivation.
e)Soil crust problem: In case of red soils, the formation of hard surface. Soil layer hinders
the emergence of seedlings, which ultimately affect the plant population. Crusting of soil
Zone Average annual rainfall
(mm)
Per cent of geographical
area
Zone I
(very low rainfall area)
< 350 13
Zone II
(low rainfall area)
350 to 750 22
Zone III
(Medium rainfall area)
750 to 1125 36
Zone IV
(High rainfall area)
> 1125 29
Table 2.1 Classification of India into different zones based on rainfall

surface after rainfall reduces infiltration and storage of rainfall, resulting in high run off.
f) Presence of hard layers and deep cracks: Presence of hard layers (pans) in soil and deep
cracks affect the crop production especially in case of black soils.
2.1.3 Lack of suitable varieties: Most of the crop varieties available for cultivation in dry
lands are meant for irrigated agriculture. There are no any special varieties exclusively meant
for dryland areas. Hence still more efforts are required to develop varieties in different crops
exclusively meant for dryland agriculture.
2.1.4 Traditional Cultivation practices
The existing management practices adopted by the farmers are evolved based on long
term experience by the farmers.
The traditional management practices are still followed by farmers leading to low yields.
• Ploughing along the slope
• Broadcasting seeds/ sowing behind the country plough leading to poor as well as
uneven plant stand
• Monsoon sowing
• Choice of crops based on rainfall
• Application FYM in limited quantity
• Untimely weeding
• Low productive cropping systems
• Inadequate nutrient supply
• Traditional storage system
3.1.5 Heavy weed infestation: This is the most serious problem in dryland areas.
Unfortunately, the environment congenial for crop growth is also congenial for weed
growth. Weed seeds germinate earlier than crop seeds and try to suppress the crop
growth. The weed problem is high in rainfed areas because of continuous rains and
acute shortage of labour. The weed suppression in the early stage of crop growth is required
to reduce the decrease in crop yields.
a) Less access to inputs, poor organizational structure for input supply
b)Non availability of credit in time
c) The risk bearing capacity of dryland farmer is very low
3.1.6 Resource constraints
1. Most of the resource for dry land are run under subsistence level of farming
2. There is less intention to adopt new technologies in dry lands among the farmers.
3. Occurrence of frequent drought for flood in dry farming areas
4. Uncertainty and is distributed rainfall and mid-season break in monsoon leading to crop
failure
5. Difficulties in adoption of new cropping pattern for cropping systems to suit the
monsoon and its behaviour
6. Absence of suitable varieties, non-availability of quality seeds, inadequate nutrient
supply and problems of soil salinity and alkalinity aggravate the situation in dry farming
areas
7. Resource poor dry land farmers are not able to practice soil conservation practices and
other new technology

8. There is a limited recognition of indigenous methods of soil and water conservation
9. Poor land preparation and untimely ploughing, sowing, lake of labour and animal power
during peak season
10. Lack of adequate linkages between crop and animal components in dry farming
3.1.7 Technological constraints
1. Lack of suitable Technologies for lesser rainfall areas
2. Lack of varieties capable of yielding higher in adverse condition. Improved varieties for
high yielding varieties are found more vulnerable to moisture stress as compared to
traditional variety
3. Non-availability of seeds of improved varieties and the demand supply is found to be
80% with groundnut, 50% with Sorghum, 25% with pearl millet and 90% with forest
species
4. Problems with prediction of sowing rain
5. Laser utilization of improved machineries/ implement under dry lands leading to poor
timeliness in feel operation and crop failure/ reduced yield
6. Poor pest and disease management practices, lack of resources for the purchase,
ultimately untimely or delay control measures and lack of water for good quality water
for spray in dryland
7. Lesser adoption of alternate land use system agroforestry, alley cropping and dry land
horticulture in dry farming region
8. Inadequate extension activities reading to poor Technologies dissemination
3.1.8 Social economic constraints
1. Lack of capital, support prices for the produce, marketing facilities and credited proper
time make the farmers hesitant to adopt the technology
2. Most of the dry land farmers are resource poor which tends them to avoid risk
3. Many dry land farmers engage only limited labor , mostly family labor for most of the
farm activities
4. Prevailing social system in dry regions prevent the farmers in adopting the improved
technology
5. Non-promotion of stakeholders concept in development of dry farming
FUTURE PROSPRECTS FOR RAINFED FARMING
A. Research:
1. Proper agro-meteorological analysis of climate- soil- crop relationship for efficient crop
planning and management
2. As water harvesting systems for crop production is uneconomic including cost of runoff
and cost of storage; however, this technique is helpful to stabilize crop production in
dry land areas. Therefore, there is a great deal of scope for stabilizing production in dry
land areas by adopting water harvesting techniques on community basis.
3. Review of contingent crop planning for Major three current weather conditions and
improvement in the contingent crop planning for different zone mainly to mitigate
drought effects.
4. Importance the development and release of dual conditions high yielding varieties of
food and vegetable crops for normal monsoon season and for dryland conditions.

Availability of seeds of these varieties along with the suitable agronomic practices will
certainly improve and stabilize the production and productivity of rainfed areas.
5. Identification of improved soil and moisture conservation practices and turn off
management suited to the conditions of individual farm holding as well as the
watershed as a whole.
6. Emphasis to increase intensity of cropping by developing appropriate inter-cropping
and double cropping systems with importance on pulses and oilseeds.
7. Agro-techniques on socially acceptable cropping systems (viz; laser leveling,
application of organic manures, modified method of sowing i.e. Aqua-fertilizer drill and
FIRB system of seed bed preparation) bases are to be developed with a view to increase
the FUE/WUE, efficient weed management, tillage system and crop residue
management including INM.
8. Emphasis on site-specific research mainly to optimise the use of resources available for
conservation and utilisation of moisture under rainfed conditions.
9. Proper adoption of alternate land use system including Agro-forestry, Agro-horticulture
and fodder based cropping system in terms of diversification in cropping system is
required for saving water and for efficient water management.
10. Completion of incomplete major and minor projects and covering about 69 m ha.
cultivated under micro irrigations by 2030 is to be exercised.
B. Policy:
1. Undertake significant shift in investment from irrigated to rainfed areas, with a major
emphasis on afforestation and soil conservation project organised on a watershed basis.
2. Investment in soil conservation practices including creation of infrastructure as well as
water harvesting system such as farm ponds has to be undertaken on a village-by-
village basis.
3. Weather aberrations continue to plague dry land farmers. Since seed is the primary
input in the adoption of improved farm technologies, seed bank must be established
with Government support in order to help farmers adopt contingent strategies.
4. Draft power is a serious constraint in dry land farming. Individual farmer cannot afford
to purchase mechanical implements. In this case, a system of custom hiring in the
villages would help farmer to complete their operation timely at an affordable cost.
5. High risk is involved in rainfed farming which does not allow farmers to adopt
improved crop production technologies. Therefore, availability of crop insurance for
drought protection involving selected dry land crops should be implemented.
6. Since farm holdings are small and excessively fragmented, further division of land
should be prevented. This can be done by encouraging the development of small scale,
agro-based industries and services in the rainfed region
7. In addition to low productivity in rainfed areas there is also an acute scarcity of fodder.
Silvi -pastoral systems on marginal land should be encouraged through liberal
financing, and should be established to cope with scarcity during drought years.

x-x-x-x-x
 India receives 400 M ha m of rainwater annually (392 M ha m from rainfall and 8 M
ha m from other sources).
 Out of 400 M ha m only 105 M ha m (26.25 %) is available for utilization. Out of
which 77 M ha m (19.25 %) is available for irrigation and 19 M ha m (4.75 %) for
industries and 9 M ha m (2.25 %) for domestic utilization.
 About 160 M ha m falls on agricultural land
 Nearly 24 M ha m is available for harvesting in small scale water harvesting
structures
 About 186 M ha m goes to rivers as runoff
 Around one-fourth of the total annual rainfall is received before or after cropping
season.

Soil & Climatic Conditions Prevalent in Rainfed Areas
3 Soil & Climatic Conditions Prevalent in Rainfed Areas
Soil
Soil is the uppermost part of the earth crust containing a mixture of minerals. It is a
three-phase system containing solid, liquid and gaseous components existing in certain
equilibrium.
Ideal dry land soils
Soil texture has a profound influence on the productivity of soil. In general depth,
texture, structure, drainage conditions and soil moisture relationship are very important soil
properties, which decide the crop growth. Advantages and disadvantages of coarse and fine
textured soils regarding crop cultivation are listed in Table 3.1.
Table 3.1 Suitability of coarse and fine textured soils for dry land agriculture
Character Course textured soil Fine textured soil
1. Example Sandy soil Clay soil
2. Plant’s nutrients Low Moderate to high
3. Moisture holding capacity Less High
4. Bulk density High Low
5. Pore space Low High
6. pores Large and continuous Minute and discontinuous
7. Infiltration / Percolation Very rapid Low
8. Permeability High Slow
9. Water Stagnation Nil High
10. soil erosion Less High (Especially in slopes)
11. dry land agriculture With uniform distribution of
rainfall and sufficient
moisture conservation
measures
Preferable and possible for
double cropping in case of
stored up/residual soil
moisture
Dry land soils and their characteristics:
In India, dry land occurs in almost all the regions of the country and the major soil types in
these dry regions are red soils (Alfisols), black soils (Inceptislos and Vertisols), Laterite soils
(Ultisols) and desert soils (Aridisols). The characteristics, features of the major soil groups
and the prospects for raising crops in these soils under dry land conditions are described
hereunder.
1. Red soils (Alfisols) :
Red soil is an important soil group in India and especially in dry land. These soils are
moderately weathered and derived from granites, gneiss and other metamorphic rocks, either
in-situ or from these decomposed rock materials washed down to lower level by rain. They
are generally red or reddish brown or yellowish brown in colour due to the coating of ferric
oxides on soil particles. Morphological types are red loams and red earth with loose topsoil.
Main features of red soils are light texture, friable structure, absence of lime
concretions and free calcium carbonates and contents of soluble salts. These soils are slightly
acidic to slightly alkaline nature, medium in cation exchange capacities and near base

saturated. Dominant clay mineral is kaolinite with an admixture of illite. Red soils are well
drained with a moderate permeability. Excessive gravel, surface crust formation and
susceptibility to erosion in high slopes are some of the problems in these soils. They are low
in organic matter content and nutrients like nitrogen and phosphorus. Occasionally,
micronutrients like zinc is deficient in red soils. Potassium content in these soils is generally
adequate for raising crops and the soil pH range is 6 to 7.
Most of the red soils have been classified in the order alfisols and these type of soils occur
widely in the states of Andhra Pradesh, Bihar, Assam, TN, West Bangal, Goa, Daman, Diu
and parts of Kerala, Maharastra and Karnataka.
Crop cultivation in red soils under dry land conditions:
Rooting depth of crops is affected in the red soils as it consists of distinct gravel and
weathered rock fragments. Crops grown under red soils in dry land conditions are susceptible
to drought if the rainfall is poorly distributed during the cropping season. The soil lacks
aggregation property leading to surface roughness, rapid seal of the soil surface after rainfall
and results in soil crusting on drying. Tilling the soil is easier on wet conditions, but becomes
hard and difficult on drying. Tillage with high wetness may lead to compaction and
ploughing will be perfect only under limited soil moisture conditions.
Establishment of a good crop is risky and the rapid surface drying due to poor rainfall
distribution may affect the crop growth under dry land conditions in the red soils. Cultivation
of crops will increase the infiltration initially, but in due course, the rate of infiltration will be
reduced. Soil erosion will be less in presence of crops or vegetation in red soils and on
denudation or allowing the land, as fallow will lead to high runoff and erosion. Leaching of
nutrients is common due to its well-draining capacity, which necessitates adequate and
frequent application of nutrients in red soils.
Groundnut, sorghum, pearl millet, fox tail millet, red gram, green gram, cowpea,
castor and horse gram are suitable crops for red soils. Groundnut + red gram, Groundnut +
castor, sorghum+ red gram are the profitable intercropping systems which help in preventing
crop loss during drought years.Black soil (Vertisol/ inceptisol)
Black soils are another important group of soils that occur in dry land conditions.
They are characterized by dark Grey to black colour, high clay content, neutral to slightly
alkaline in soil reaction and developing deep cracks during summer season. These are locally
known as black cotton soil. Depth of the soil varies ranges from a low of 50 cm to several
metres and in many cases it overlies decompose rocks (parent material) known as murram.
Black soil are formed from Deccan basalt trap rocks either in-situ or on the
transported parent material. In the formation of black soils, presence of a high proportion of
alkaline earth in the weathering complex is of great importance. These soils have impeded
drainage and low permeability. It occurs in areas under monsoon climate, mostly in semi-
arid and sub humid type. High clay content and montmorillonite type of clay mineral impart
high swelling and shrinkage properties of these soils.
Black soils are low in organic matter content, available nitrogen and phosphorus and
sometimes zinc, but reach in base nutrients like calcium, magnesium and potassium. Soil pH

is in the range of 7.5 to 8.5. Soil is highly clayey and the clay content varies from 35 to 60%
and sometimes up to 80%.
Table 3.2 : Improved technologies for red soils
Sr.
No.
Technology Aims Suggestions/ Observations
1 Land & water
management
Realigning and
strengthening of
field or boundary
bunds for
conservation of
soil and water
 Establishment of vegetation cover on bunds
 Formation of graded bunds
 Growing vegetative filter strips on contours
 Summer ploughing
 Contour tillage in slope lands
 Opening of dead furrows (at 10 feet interval)
 Construction of dugout pond
 For soil depth more than 20 cm, deep tillage
once in three years for better infiltration of
rainwater and to reduce pest and weed
problems
 Mulching with agricultural waste @ 5 t/ha,
within 10 days after sowing of crop to prevent
evaporation losses.
 Water harvesting in farm ponds and
subsequent use as supplementary/ lifesaving
irrigation to increase yields of rain fed crops.
2 Crop
management
Cropping season in
coincidence with
safe period of
rainfall.
Double cropping
in deep and
medium soils
 Depending on amount and distribution of
rainfall and retention capacity of soil
 Following double cropping / intercropping /
sequential cropping
 In case of surface crusting, application of
sand @ 40 t/ha before sowing to decrease the
crust strength, to facilitate better infiltration
of water into soil and to improve germination
and crop stand
 Intercropping with pulses reduce runoff
losses, reduce soil erosion, conserve more
moisture, add more organic matter in the soil
and ultimately improves soil productivity
3 Fertility
management
Increasing the crop
response to applied
nutrients
especially
phosphorus
 Application of phosphate fertilizers
 Application of nitrogen in splits with
sufficient moisture
 Crop residue addition to improve soil
physical properties
 Addition of other nutrients as per soil test
These soils are characterized by high swelling and shrinkage, plasticity and
stickiness. Black soils are generally calcareous neutral to slightly alkaline in reaction, high
base status and high cation exchange capacity. They possess high soil moisture holding
capacity. Runoff is severe in black soil and it is prone to erosion and the soil loss is estimated
to be in the range of 6 to 8 t/ha per year. Shallow black soils on slopes have been classified in

the order of Entisolsl and Inceptisols, while the deep medium black soils in the order of
Vertisols. Black soil occur extensively in the states of Maharashtra, Madhya Pradesh and
parts of Andhra Pradesh, Gujarat and Tamilnadu
Table- 3.3 : Improved Technologies for black soil
Sr.
No.
Technology Aims Suggestions/Observations
1 Land & Water
management
 Promotion of intake
of water in soil
 Improvement of
aeration and
workability
 Reduction in soil
erosion and runoff
 Facilitation of safe
disposal of excess
water
 Construction of water storage structures
like farm ponds
 Following watershed concept
 Application of FYM @ 20 tons per
hectare for better infiltration of water
 Formation of graded Bund
 Formation of a channel with a slope of.1-
0.25% along the graded Bund and
merging this channels into a grassed
waterway to drain water without any soil
erosion
2 Land
configuration
 Reduction in Runoff  Rough with ridges and furrow to
facilitate ponding of water
3 Dry season
tillage
 loosening of soil after
harvest of post rainy
season crop
 Blade harrowing after receipt of Pre-
monsoon rain to break clods
4 Pre-monsoon
dry seedling
 Utilisation of first
rain, ensuring early
establishment of
crops and reduction in
the difficulty in
planting in wet and
sticky soil
 Placing seeds in 5 cm death
 Good results reported in crops of
sorghum, cotton, main sunflower iI,
green gram, red gram and poor results
reported in in pearl millet, soybean and
groundnut
5 Improved
cropping
system
 Increasing the crop
productivity and
Returns
 Best suited to areas with moderately
dependable and favourable rainfall>750
mm
6 Fertility
management
 Increasing the crop
response to applied
nutrients especially
nitrogen
 Recommendation as per soil test/
application of nitrogenous fertilizers
7 Pest
management
 Low cost and
maintenance of
environment
(pesticides used only
at threshold level of
pests)
 Following integrated pest management
practices
Crop cultivation in black soils and dry land conditions
A large area with Vertisols is under dryland conditions in India. Black soil is more
productive than red soil. Important crops grown under the soils are coarse grains, cotton,
oilseeds and pulses. Growing of crops is possible during post-rainy season (rabi season) with
stored up soil moisture in shallow black soils (Entisols). In case of medium and deep black
soils (i.e. Vertisols/ Inceptisols), growing crops is possible in season and post rainy season

which stored up soil moisture (double cropping) depending on the quantity and distribution of
rainfall. Cotton, Sorghum and other millets, pulses; especially chickpea, chillies, sunflower,
safflower and coriander are suitable crops.
Laterite soils (Ultisols)
Laterite soils are well-drained soil with good hydraulic conductivity. They are formed
by soil forming process called laterization. Laterite is a geological term, which means
literally rock. Under high rainfall conditions, silica is released and leached downwards and
upper horizons of the soil become rich in oxides of iron and Aluminium. This process is
called laterization . Laterites are subdivided into high and low level laterites. High level
laterites are found capping the summits of hills and plateau of the high lands and they are not
useful for agriculture as they are thin and gravely. Low level laterites comprising of clay and
loam occur in coastal regions on both sides of the peninsular region and are of considerable
agricultural importance. Laterization is intensified with increase in rainfall with low intensity.
Texture of a laterite soil is generally loam in top layers and depth of the loamy layer
varies and in eroded nature. These soils are Pale, gritty, shallow and poor in plant nutrients in
top layer. Soils in lower layers are of fine texture, darker and rich in plant nutrients and
organic matter. All laterite soils are very poor in base materials like calcium and magnesium.
The pH of the soil is low and acidic in nature. Soil clay type is generally kaolinite with traces
of illite. Most of the laterite soils are classified under the order ultisols. These soils are well
developed on the summits of Hills of the Deccan, Karnataka, Kerala and Madhya Pradesh,
the Ghat regions of Orissa, Maharashtra, Kerala, West Bengal, Tamil Nadu and Assam.
Crop cultivation in laterite soils under dry land conditions
At lower elevations, suitable crops for cultivation under dryland conditions are rice
(either single or double cropping), minor millets, trees and shrubs. Soil and moisture
conservation measures may become necessary in regions of low to medium rainfall. At higher
elevation in laterite soil plantation crops like tea, coffee, cinchona, rubber and cashew are
grown.
Desert soil (Aridisols)
These soils occur in hot desert region in India. Rainfall of the region is ranging from
as low as 50 mm to the highest of 400 mm of which the major portion is received during
monsoon season. Potential evapo-transpiration is very high and showing aridity. A major part
of the region consists of sand dunes and undulations. A zone of accumulation of lime
concretions at a depth of 60 to 120 cm and presence of alkaline earth carbonate are common
futures of this type of soils. Clay content is very low ranging between 2 to 8% and presence
of sodium clay make the soil susceptible to dispersion and less permeable. The pH of the soil
ranges from 8 to 9. Clay type is illite with small amounts of kaolinite. Desert soils are
classified under the order Aridisols. These soils are distributed in the regions of Rajasthan,
southern Haryana and Punjab and northern Gujarat.
Crop cultivation in desert soils under dryland conditions
Soils are light textured and the moisture holding capacity and nutrient availability are
less. They are generally poor in available nitrogen and phosphorus. Soil salinity is a common
problem and effective soil depth is influenced by the presence of calcium and carbonate
concretions at various depth. Crop cultivation is possible only in deep soils either during
kharif or rabi season based on the rainfall quantity and its distribution.

Sub-Montane Soils
Sub-montane soils occur in undulating lands of sub Himalayan regions under
coniferous forest. Regions with sub-montane soils are characterized by high rainfall,
accumulation of organic matter, absence of free lime and acidic nature. Landslides and soil
erosion arecommon problems associated with sub-montane soils which lead to the leaching of
bases.
Crop cultivation in sub-montane soils under dry land conditions
Soil moisture storage varies from 20 to 30 cm per metre soil profile. As the regions
are characterized by high rainfall, double cropping is possible in sub-montane soils. Soils are
low in available nitrogen and phosphorus and crops respond well to the application of N and
P for higher productivity.
Saline and sodic soils
Saline and sodic soils occur mainly in arid and semi-arid regions of the country
where the annual temperature are high and rate of evaporation generally exceeds rainfall. The
situation leads to accumulation of salts in surface layers of the soil. In India, such soils are
spreading over 8.5 million hectare of land and they are found with poor organic carbon,
available nitrogen and Zinc.
Saline soils contain excessively soluble salts and the dominant soil type are chlorides
and sulphates of sodium, magnesium and Calcium. Total salt concentration as expressed by
soil EC is generally more than 4 dS/ m. These soils are associated with water logging, saline
groundwater and aridity.
Sodic soils generally contain salts of carbonates and bicarbonates of sodium where the
soil EC will be less than 4 dS/m and exchangeable sodium percentage more than 15%. These
soils can be observed with stagnation of muddy water after rain for many days and they are
very hard when dry and very soft when wet. Sodic soils contain insoluble calcium carbonate
at high pH level (>9.5).
Crop cultivation in saline sodic soils under dry farming conditions
Reclamation Technologies for growing crops in Salt affected soil differ depending
upon the availability of source of water. For areas which depend only on rainfall as the source
of moisture, cultivation of salt tolerant plants species and planting techniques are
recommended. Crops have been identified to salt stress conditions and few such crops which
are sensitive and tolerant to soil salinity and sodicity under dry land conditions are given in
table 3.4.
Table 3.4 : Sensitive and tolerant to soil salinity and sodicity under dry land conditions
Saline soils Alkaline/ sodic soil
Sensitive Tolerant Tolerant
Highly sensitive
Legumes like green gram,
black gram, lentil, gram and
peas
Moderate sensitive
Major and minor millets
Highly tolerant
Direct sown rice, wheat,
pearl millet, barley, oats,
mustard
Medium Tolerant
Sunflower, cotton, kernel
grass, Trees like acacia,
tamarind, ber
Beans, rice, grasses like
Rhodes grass, barley, wheat,
cotton, trees like Amla, ber,
Eucalyptus hybrid, Dalbergia
sissoo, Terminalia arjuna

Climate
The behaviour of atmospheric phenomenon at a given place and time is defined as
weather and the composite day-to-day weather elements for a given place or region over a
period is referred as climate.
Dry climate
A dry climate is one in which the average annual precipitation is definition in relation
to evaporation. It can be divided into arid and semi-arid climate.
Arid climate
It can be defined as an extreme dry climate where the average annual precipitation is
less than 500 mm and usually in the range of 250 82500 mm. Generally, the rainfall is well
short of evapotranspiration demand of the atmosphere. The precipitation is insufficient for
crop production.
Semi-arid climate
It can be defined as a climate where the average annual precipitation is greater than
500 mm and generally, crop production is possible with dry farming methods or with
supplemental irrigation.
The tropical retreat and semi-arid climate I have many features in common the
distinct character of this climate is lake of sufficient rainfall to sustain crop production. They
are centre on the latitudes from 20 to 25 degree north and South.
Climate largely limits crop and animal production, ensures the human comfort,
influences on health determine clothing and housing etc. Its influence on agriculture is
enormous throughout the world and in a country like India where agriculture is the backbone
of development, importance is manifold. The success of failure of farming is closely related
to the prevailing weather condition. However, there are possibilities to optimise farm
production by existing cropping pattern and agronomic practices to suit the climate of a
locality. Weather resumes significance in nearly every phase of Agricultural activity from the
preparatory tillage to harvesting and storage. Therefore, a sound knowledge of climate factors
and an understanding of the complex processes of interaction between the climate and the
biological processes of the plants are essential to a scientific approach on farming. The
principal climatic factors limiting crop production in the order of priority under dryland
conditions are precipitation temperature, sunlight, wind length of growing season etc.
1. Effect of precipitation in dryland
The common forms of precipitation are drizzle, rain, snow, sleet and hail. In dry lands rainfall
limitation is the greatest factor in influencing the crop growth and yield. Rainfall plays a
major role in determining the real potential of a crop and the region. It also has an influence
on deciding the sequence and timing of farming operation and farming system
General advantages of precipitation
 Recharge of groundwater
 Decision on various agricultural operations
 Decision on pattern of land utilisation
 Selection of crops, varieties, cropping and farming system
 Storage in reservoirs
 Decision on vegetation
 Development of irrigation sources
 Hydro power generation..

Forms of precipitation and their effect on crop growth.
General forms of precipitation are rainfall, snow and hail. Their common characteristics in
dry regions and its effects on crop growth are discussed as under.
Table 3.5 Rainfall and its characteristics in dry lands
Characteristics Effects on crop growth
General In dry
region
General effects If excess If deficient
1.Seasonal
distribution
2.
Dependability
3. Frequency
4. Intensity
1. Highly
unreliable
2. Frequency
less
1. Intensity
more
3. Highly
seasonal
(maximum
in winter)
4. Often
insufficien
t
1. High intensity and
heavy rainfall
a. Denudation and soil
erosion
b. Run off and floods
c. Destruction of soil
crumbs
d. Loss of soil fertility
e. Loss of soil fertility
f. Poor germination,
pollination and
flowering
2. Wet weather due to
rainfall leading to pest
spread
3. Failure or poor
rainfall
a. Soil
salinity/alkalinity
b. Crop loss/ damage
1. Run off
2. Leaching of
plant
nutrients
3. Reduction in
germination
4. Crop
lodging
5. Impair in
pollination
6. Crops
affected by
anaerobic
conditions
1. Drought
2. Yield loss
3. Problem
soils
4. Famine
5. Crop
damage
Table 3.6 Hail and its characteristics in dry lands
Characteristics General effects Effects in crop
growth
General In dry regions
1.Rare occurrence
in tropics
2.Rare occurrence
in high latitudes
3.Common in warm
season
1.Common in sub-
montane areas in
India
2.Rare occurrence
in southwest
monsoon season
1.Floods under high
temperature/storms
2.Road or path
closure
3.Mechanical damage
to trees
4.Hazards to air crafts
1. Mechanical
damage to plants
2. Shredding of leaves
3. Shattering of
flower and seed
heads
2. Effect of solar radiation in dry lands
Sun is a primary source of heat and light on the earth and radiant energy striking the
earth is called as insolation. The insolation consists of the sunlight and temperature, which act
as the important factors of weather and climate. Distribution of insolation is closely related to
latitude and it is greater at equator and decrease towards poles regularly. Influence of solar
radiation decides the rate at which plants develop at various stages of growth. Every crop has
limitations in their temperature and sun light requirements.

Table 3.7 Snow and its characteristics in dry lands
Characteristics General effects Effects in crop
growth
General In dry regions
1. Present in
mountainous
regions in mid-
latitudes
2. Release by
rising
temperature
3. Ground water
recharge
4. Generally more
on leeward side
of mountains
and uplands
from oceans
Significant to water
users in arid lands
adjacent to snow-
capped mountains
1. Floods under high
temperature/ storms
2. Road or path
closure
3. Mechanical damage
to trees
4. Problems in
housing
5. Sheet or reel type
of erosion
1. Run off
2. Soil erosion
3. Suffocation to
crop plants
Table 3.8. Sunlight and its characteristics in dry lands
Duration (Relative length
of day and light
Intensity Quality (Wave length)
1.General Characteristics
a. Varies with latitude and
season
b. Equal day and night at
equator
c. Day light ranging from
zero (winter to 24 hours
(summer) at polar regions
d. Crops flowering behaviour
depends on duration of
light
e. Division as short day, long
day and day neutral plants
2. Effects on crop growth in
arid region
a. Arid and semi-arid crops
are mostly short day plants
(< 10 hours) and they
require long nights for
flowering
b. Most sun shine in dry
areas (20-300
latitude on
both sides).
c. More dry matter
production (if moisture is
not a limiting factor).
1. General Characteristics
a. Energy source for whole
plant process
b. Extreme low (< 500
candles) and extreme high
intensities inhibit
photosynthesis.
2. Effect on crop growth
a. Light intensity indirectly
affect productivity by its
effect on leaf temperature
1. General Characteristics
a. Wave length ranging from
0 to 0.25 micron is
harmful to plants
b. Wave length ranging from
0.30 to 0.55 micron has
photoperiodic effect
c. Wave length ranging from
0.40 to 0.79 micron is
good for photosynthesis
d. Wave length more than
0.79 micron has no effect
on photosynthesis

Table 3.9 Effect of temperature and its characteristics in dry lands
General Characteristics Characteristics in arid
regions
Effects on crop growth
1. Decrease from equator to
poles
2. Wind direction and
movement influence mean
temperature in a locality
3. Mountains act as barriers
on horizontal temperature
distribution
4. Temperature reduction by
3.30
F for every 1000 feet
elevation.
1. Seasonal higher
2. Diurnal variation more
3. Highest in arid and semi-
arid tropical climates
4. Occasionally below
freezing temperature in
tropical deserts
5. Lesser at higher attitudes
in arid and semi-arid
climates.
1. Temperature limit for each
stage of every crop
2. High temperature is not a
serious problem if soil
moisture is adequate
3. Slow or stop in growth rate
at very high temperature
4. Premature fall of leaves
and fruits
5. Prolonged chilling or
freezing reduce water flow
in plants leading to
retardation or killing
6. Disastrous dry and hot
conditions
7. Increases evapo-
transpiration and water
requirements of the crops
8. Influences multiplication
of insects and pathogens
3. Effect of wind in dry lands
General effects of wind
 Favours cross pollination
 Affects pollination by insects
 Causes mechanical damage to plants
 Leading to shattering of flowers and seeds
 Stripping of fruits and nuts
 Dispersal of weed seed
 Wind erosion and removal of soil fertility
 Increase evapo-transpiration
 Reduces germination (by covering seeds)
 Prevention of frost (on occasions)
 Dispersal of pollen and seeds
 Decides monsoon pattern
 Desiccation of plants
 Blow from desert may have reduction in photosynthesis and translocation of food
materials
 Influence migration of insects and pathogens

Various types of wind are gale, storm and hurricane and their sub types. They have
differential effects on crop growth.
Table 3.10 Gale and its effects
Types of Gale Speed (km/hour) General effects
1. Moderate gale
2. Fresh gale
3. Strong gale
4. Whole gale
56 to 60
61 to 74
75 to 88
89 to 102
1. Swaying to uprooting of trees
2. Slight to heavy structural damage
3. Causing obstructions to traffic
Table 3.11 Storm and its effect
Type of storm General Characteristics General effects
1. Thunder storms (89 to
102 km/hr)
1. Unknown polar regions
2. Diameter from 5 to 35
miles
3. Heavy rainfall with large
drops
4. Chances of
hail/snow/snow pellets
5. Thunder storm followed
by lighting
1. Severe damage to air
planes in flight
2. Run off and severe soil
erosion
3. Tornadoes (102 to 117
km/hr)
1. Violent storms
2. Maximum width of one
to two miles
3. Accompanied by thunder
storms, rain, hail and
lighting
4. Funnel shaped column
from the base of the
cloud
5. Funnel diameter of 50 m
or more
1. Unbelievable destruction
in its pathways including
explosion of buildings
Table 3.12 Hurricane and its effects
General Characteristics General Effects
1. Speed in the range of 117 to 132 km/hr.
2. Energy depends on moisture content in
warm air
3. Diameter from 100 to 6000 miles/hr
(minimum of 25 miles/hr)
4. Eye diameter from 5 to 30 miles
5. Also called cyclones, typhoons and
tropical storms
1. Structural destruction
2. Flooding
3. Shipping affected

4. Effect of other climatic factors
a. Humidity
Humidity refers the measure of moisture content in atmosphere and it plays a
significant role in climate and weather. Air can hold a certain quantity of water
vapour at a given temperature and several expressions are used for denoting the
humidity. They are…
1. Specific humidity : It can be defined as the ratio of the mass of water vapour
actually in the air to unit mass of air
2. Dew point or Saturated Vapour Pressure :It is all the water vapour that can be
held by the air at a given temperature and pressure.
3. Absolute humidity : It is defined as the actual amount of water vapour in the air.
4. Relative Humidity ; It is referred as the ratio of water vapour actually present in
the atmosphere to the amount of water vapour required for saturating it ay that
temperature (expressed in percentage).
Among these expressions, the best known and mostly used reference to water vapour
is relative humidity (RH%) and it is found to be maximum during early morning
hours and the minimum is afternoon.
Table 3.13 : Humidity and its characteristics in dry lands
General Characteristics Characteristics in arid
region
Effects in crop growth
1. Greater on land surface in
winter
2. RH will increase on
decreasing temperatures
3. Low specific humidity in
polar regions
1. RH low in arid regions (12
to 30 %)
2. High RH may compensate
low rainfall in part
3. RH depends on direction
of prevailing winds in
semi arid regions
4. Absolute humidity will
always be low
1. Evaporation will be less
under high RH condition
2. Plants can withstand low
humidity if soil moisture
is adequate
3. Water requirement of
crops can be decided with
prevailing RH
b. Dew :
Dew formation mostly occurs at night because of its dependence on radiational
cooling of leaf and soil surface. Clear sky, low wind speed, high atmospheric humidity and
vegetation of low heat capacity are the main factors contributing to dew formation. The
absorption of dew by the plants depends on type of plant species, its intensity, duration of
dewfall and soil moisture conditions. Under moisture deficit conditions, effect of dew is
important as it can accelerate the restoration of turgor pressure at night and delay the stress at
day time.
ECO SYSTEMS UNDER ARID AND SEMI ARID CONDITIONS IN INDIA
A. ARID ECOSYSTEM
Agro eco region number 1 (cold arid eco region)
Location: North Western Himalayas covering Ladakh and Gilgit districts of Jammu and
Kashmir and consisting of 15.2 million hectare.

Climate: Mild summer and severe winter with the mean annual rainfall less than 150 mm.
Precipitation is always lesser than potential evapotranspiration.
Soil type: skeletal and calcareous soils with alkalinity and low to medium organic matter
content.
Land use: Sparse forest trees. Regular cropping programs include vegetables, millet, wheat,
fodder, pulses, barley and fruit crops like apple and apricot.
Livestock: Dominated by mule and followed by sheep, goat and yak rearing.
Constraints:
 Severe climatic conditions limiting crop growth
 Length of growing season is less than 90 days in a year which limits crop production
 Nutrient imbalance due to Sandy and gravelly and moderate to calcareous soil
Rain: Water vapour condenses around condensation nuclei (such as dust) and falls when the
droplet is heavy enough.
Sleet: Same formation as rain, but it freezes somewhere along its path from the clouds to the
ground. Sleet is a mixture of snow and rain.
Snow: Water droplets form and then freezing occurs slowly, allowing for the development of
uniquely designed ice crystals know as snow. Snow is formed when water vapour is deposited in
the higher reaches of the atmosphere at a temperature less than zero degrees Centigrade, and then
falls to the ground. Snowflakes are typically symmetrical, hexagonally shaped groups of ice
crystals that form while falling in and below clouds. Simply put - Snow forms if the air in a
cloud is below freezing. The water vapour then turns to ice instead of rain and the tiny ice
crystals stick together until they form snowflakes. When they get heavy enough to fall, they drop
out of the clouds. At this point though, we still don’t know whether they will end up as rain or
remain as snow. This depends on the temperature of the air they travel through on the way down
to the ground. If it gets warmer, they turn into rain, but if the air stays close to freezing all the
way down, then the snowflakes will make it without melting and so fall as snow. If this occurs in
a mountain area, it is possible for snow to be falling on the mountaintop while lower down in the
valley the air is warmer and so it is raining instead.
Hail: Water droplets are carried high into the atmosphere by thunderstorm updrafts, which cause
them to freeze. Multiple drops tend to freeze together, which is why the diameter of hail can be
large.
Dew: Water vapour on the ground condenses on objects such as blades of grass when the surface
temperature is equal to the dew point
Frost: Dew forms and then it freezes. This commonly occurs when nigh time. Radiational
cooling drops the ground temperature down enough. There are three kinds of frost: Delicate
crystallized ice on windowpanes is called Hoar frost. Glazed frost consists of thick coatings of
ice on cold surfaces. Rime frost is formed when super-cooled water droplets freeze on contact
with cold surfaces. It often occurs when freezing fogs or drizzle blanket the ground.
Freezing rain: Forms and falls as rain. At the surface or near the surface, the temperature is at or
below freezing, which causes the rain to freeze on contact.
Fog: A thin cloud of varying size formed at the surface of the earth by condensation of
atmospheric vapour.
Mist: A very thin fog.
Drizzle: A light steady rain in fine drops (0.5 mm) and intensity < 1 mm/hr.

Potential of the region
 Dry fruit crops apricot and off season vegetables peas
Fig. 3.1 Arid and semiarid zones of India
Agro Eco region number 2 (Hot arid eco region 1)
Location : South western part of Punjab and Haryana, Western parts of Rajasthan, kutch and
North kathiyawad Peninsula in Gujarat. Area under this Zone extends to 31.9 million
hectares.
Climate: Hot summer and cold winters with a minimum annual rainfall less than 400 mm.
Potential evapotranspiration demand ranges between 1500 and 2000 mm annually. Length of
growing season is less than 90 days per year.
Soil type: Desert and Sandy soils with calcareous and alkaline nature
Vegetation and cropping pattern: Drastically reduced, spares and tropical thorn forest.
Rainfed mono-cropping with short duration crops like pearl millet and pulses. In irrigated
land crops like sugar cane, cotton, mustard, gram and wheat are grown.
Constraints:
 Indiscriminate deforestation
 Scanty and Erratic rainfall pattern leading to draught at critical stages of Crop growth
 Soil salinity and nutrient imbalance
Potential of the zone
 Developing irrigation sources can further increase the productivity
 Dryland Agroforestry and forestry may sustain the productivity
Hot arid eco region 2
Location: Deccan Plateau covering the districts of Bellary , Tumkur, North Chitradurga,
South west parts of Bijapur, Raichur of Karnataka and Anantapur of Andhra Pradesh. The
total spread of the region is 4.9 million hectares.

Climate: Hot and dry summer and mild winters with the mean annual rainfall ranging from
400 to 500 mm. Severe drought prone area throughout the year and length of growing period
is less than 90 days in a year.
Soil type: Shadow to medium red loam soil and deep clayey black soil
Vegetation and cropping pattern: Tropical dry deciduous and tropical thorn forests.
Irrigated farming includes growing of sugarcane, cotton, safflower and groundnut. Rainfed
Mono-cropping is carried out with during rainy season pearl millet or post rainy season with
stored residual moisture sorghum or safflower
Constraint:
 Soil erosion during rainy season
 Poor and ill distributed rainfall and occasional crop failure due to prolonged dry spell
 Poor Workability of black soil
SEMI ARID ECOSYSTEM
Agro Eco region number 4 (Hot semi-arid eco region 1)
Location: Parts of Gujarat (5 districts), Haryana (8 districts), Punjab (7 districts), Union
Territory of Delhi, Uttar Pradesh (29 districts) and Rajasthan (11 districts). This region
extends to 2.2 million hectares.
Climate: Hot and dry summers and cold winters with the mean annual rainfall ranging
between 500 to 1000 mm. Length of growing period is 90 to 150 days in a year.
Soil type: Course to fine loam and sand dunes
Vegetation and cropping pattern: Tropical deciduous and tropical thorn forest. Irrigated
farming is followed in 65% of the total cultivable area and the crops cultivated are wheat,
rice, millet, maize, pulses, berseem, mustard and sugarcane. Rainfed agriculture is followed
in 35% of the area with mono-cropping of seasonal crops like sorghum, soybean and pigeon
pea and post seasonal crops like ok pulses, lentil and wheat on residual moisture.
Constraints:
 Nature of soil with low water holding capacity
 Lowering water table
 Salinity and sodicity due to in perfect drainage condition
Potential of the region:
 Introduction of irrigation facilities and changes in cropping pattern from low value
crops like millets to high value crops like cotton, sugarcane and wheat
 Crop diversification to oil seeds
Location: Western Madhya Pradesh (10 districts), South Eastern parts of Rajasthan (5
districts) and Gujarat (10 districts) and Union Territory of Diu. This zone covers 17.6 million
hectares.
Climate: Hot and wet summer and cold winter with a mean annual rainfall of 500 to 1000
mm and the length of growing period 90 to 150 days. Certain districts of the states of Madhya
Pradesh, Rajasthan and Gujarat are prone to drought once in three years.
Soil type: Deep loam to clay and black soils. Coastal areas in Gujarat have clay and sandy
soils with slight alkalinity.
Vegetation and cropping pattern: This region is characterized by dry deciduous forest. Dry
farming is practised in most areas with kharif crops like sorghum, pearl millet, pigeon pea,

groundnut, soybean, maize and pulses and with Rabi crops like safflower, sunflower and
gram
Constraints:
 Intermittent or occasional drought occurrence
 Soil salinity or alkalinity due to imperfect drainage or inundation of seawater leading
to crop failure
 Development through minor irrigation project
 Forestry and dryland horticulture activities
Agro Eco region number 6 hot semi-arid eco region 3)
Location: Western parts of Maharashtra (20 districts), Northern parts of Karnataka (6
districts) and Western parts of Andhra Pradesh (2 districts). The zone spreads over 31 million
hectares.
Climate: Hot and humid summer and mild and dry winter with an annual rainfall of 600 to
1000 mm. Length of growing period is between 90 and 150 days. Some districts are drought
prone and the drought spell may be severe once in 3 years.
Soil type: Shallow loam to Clay soils with calcareous or alkaline nature
Vegetation and cropping pattern: The region is found with tropical dry deciduous tropical
thorn forest. Mono-cropping is followed under rainfed condition with kharif crops like pearl
millet or post rainy season crops like safflower and sunflower. With irrigation facilities crops
like cotton and groundnut are grown.
Constraints :
 Prolonged dry spells leading to reduced growth and crop failure
 Soil erosion
 Nutrient imbalance in soil
Potential of the region :
 Achievable high productivity with better water management practices
 Dryland Agroforestry and horticulture
Location: Deccan Plateau and Eastern parts of Andhra Pradesh (14 districts). This region
spreads over 16.5 million hectares.
Climate : Hot and moist summer and mild and dry winter with the mean annual rainfall of
600 to 1100 mm. Length of the growing period is ranging between 90 and 150 days in a year.
In this zone 6 districts are prone to drought.
Soil type: Black cotton soils are calcareous and strong alkaline in nature. Isolated track are
found with red soils, which is non-calcareous and neutral in reaction.
Vegetation and cropping pattern : Tropical dry deciduous and thorny forest. Traditional
farming under rainfed condition is followed with kharif crops like sorghum, cotton, pigeon
pea, rice, groundnut and castor and rabi crops like sorghum, sunflower, safflower and other
oil seeds, rice is the major crop under irrigated condition.
Constraint:
 Soil erosion due to high runoff leading to loss of soil and nutrients
 Crop failure due to frequent drought under rainfed condition
 Imperfect drainage under irrigated conditions leading to salinity and sodicity

 Achievable high productivity with better water management practices
 Dryland Agroforestry and horticulture
 Watershed program
Agro Eco region number 8 (Hot semi-arid eco region 5 )
Location : Eastern Ghats and Southern parts of Deccan Plateau covering the parts of Andhra
Pradesh (one district), Karnataka (9 districts) and Tamil Nadu (15 districts) and extending
over an area of 19.1 million hectares.
Climate: Hot and dry summer and mild winter with a mean annual rainfall of 600 to 1000
mm and the length of growing period is 90 to 150 days in a year. Parts of Karnataka receive
rainfall in summer season and rest of the region receives rain during winter.
Soil type: Red loamy soil
Vegetation and cropping pattern: Tropical dry deciduous and thorny forest. Under irrigated
conditions, cotton, sugar cane and rice are the major crops. Rainfed cultivation is the
traditional practice with crops like millets, pulses and oilseeds especially groundnut in kharif
season and with crops like sorghum and oilseeds especially safflower in Karnataka in Rabi
season.
Constraints:
 Severity of soil erosion
 Severity of drought due to poor moisture holding capacity of soil
 Dryland Horticulture with suitable fruit crops
 Floriculture under irrigated condition
x-x-x-x-x

Soil Erosion: Soil and Water Conservation Techniques
4 Soil Erosion:
Soil and Water Conservation Techniques
Soil erosion:
Soil erosion is the process of detachment of soil particles from the top soil and
transportation of the detached soil particles by wind and / or water.
The agents causing erosion are wind and water. The detaching agents are falling
raindrop, channel flow and wind. The transporting agents are flowing water, rain splash and
wind.
Nature and extent of erosion
The problem of soil erosion exists all over the country. Out of the 329 m. ha of India’s
geographical area about 175 m. ha (53.3%) is subjected to soil erosion and some kind of land
degradation (Druvanarayana, 1993). About 150 m. ha is subjected to wind and water erosion.
It is estimated that about 5333 Mt of soil is detached annually. Out of this 29 % is carried
away by rivers to seas and about 10% is deposited in reservoirs resulting in 1-2 % of loss of
storage capacity annually. The estimated annual soil loss is 16.35 tones /ha/year.
Losses due to erosion
i Loss of fertile top soil vi Reduction in soil depth
ii Loss of rain water Vii Floods
iii Loss of nutrients Viii Adverse effect on public health
iv Silting up of reservoirs ix Loss of fertile land
v Damage to forests x Economic losses
Types of erosion:
There are two major types of soil erosion
a) Geological erosion (Natural or normal erosion): is said to be in equilibrium with soil
forming process. It takes place under natural vegetative cover completely undisturbed by
biotic factors. This is very slow process.
b) Accelerated erosion: is due to disturbance in natural equilibrium by the activities of man
and animals through land mismanagement, destructing of forests over grazing etc., Soil loss
through erosion is more than the soil formed due to soil forming process.
Based on the agents causing erosion, erosion is divided into
a. Water erosion b. Wind erosion c. Wave erosion
A. Water erosion
Loss of soil from land surface by water including run off from melted snow and ice is
usually referred to as water erosion.
Major erosive agents in water erosion are impacting/ falling raindrops and runoff
water flowing over soil surface.
Process of water erosion
Detachment of soil particles is by either raindrop impact or flowing water. Individual
raindrops strike the soil surface at velocities up to 9 m/s creating very intensive
hydrodynamic force at the point of impact leading to soil particle detachment. Over land flow

detaches soil particles when their erosive hydrodynamic force exceeds the resistance of soil
to erosion. Detached soil particles are transported by raindrop splash and runoff. The amount
of soil transported by runoff is more than due to raindrop splash. Thus the falling raindrops
break the soil aggregates and detach soil particles from each other. The finer particles (silt
and clay) block the soil pores and increase the rate of runoff and hence loss of water and soil.
Forms/Types of water erosion
Water erosion occurs in stages identified as sheet erosion, rills, gullies, ravines,
landslides and stream bank erosion.
a) Sheet erosion: It is the uniform removal of surface soil in thin layers by rainfall and runoff
water. The breaking action of raindrop combined with surface flow is the major cause of
sheet erosion. It is the first stage of erosion and is least conspicuous, but the most
extensive.
b) Rill erosion: When runoff starts, channelization begins and erosion is no longer uniform.
Raindrop impact does not directly detach any particles below flow line in rills but
increases the detachment and transportation capacity of the flow. Rill erosion starts when
the runoff exceeds 0.3 to 0.7 mm/s. Incisions are formed on the ground due to runoff and
erosion is more apparent than sheet erosion. This is the second stage of erosion. Rills are
small channels, which can be removed by timely normal tillage operations.
c) Gully erosion: It is the advanced stage of water erosion. Size of the unchecked rills
increases due to runoff. Gullies are formed when channelized runoff form vast sloping
land is sufficient in volume and velocity to cut deep and wide channels. Gullies are the
spectacular symptoms of erosion. If unchecked in time no scope for arable crop
production.
d) Ravines: They are the manifestations of a prolonged process of gully erosion. They are
typically found in deep alluvial soils. They are deep and wide gullies indicating advanced
stage of gully erosion.
e) Landslides: Landslides occur in mountain slopes, when the slope exceeds 20% and width
is 6 m. Generally, landslides cause blockage of traffic in ghat roads.
f) Stream bank erosion: Small streams, rivulets, torrents (hill streams) are subjected to
stream bank erosion due to obstruction of their flow. Vegetation sprouts when streams dry
up and obstructs the flow causing cutting of bank or changing of flow course.
Factors affecting water erosion
a) Climate: Water erosion is directly a function of rainfall and runoff. Amount, duration and
distribution of rainfall influences runoff and erosion. High intensity rains of longer duration
causes severe erosion. Greater the intensity, larger the size of the raindrop. Rainfall intensity
more than 5 cm/hr is considered as severe. Total energy of raindrops falling over a hectare
land with rainfall intensity of 5 cm /hr is equal to 625 H.P. This energy can lift 89 times the
surface 17.5 cm of soil from one ha to a height of 3 ft. Two- thirds of the above energy is
used for sealing soil pores. Runoff may occur without erosion but there is no water erosion
without runoff. The raindrop thus breaks down soil aggregates, detaches soil particles and
leads the rainwater with the fine particles. These fine particles seal the pores of the surface
soil and increases runoff causing erosion.
b) Topography: The degree, length and curvature of slope determine the amount of runoff
and extent of erosion. Water flows slowly over a gentle slope where as at a faster rate over a

steeper one. As water flows down the slope, it accelerates under the forces of gravity. When
runoff attains a velocity of about 1 m/s it is capable of eroding the soil. If the percent of slope
is increased by 4 times the velocity of water flowing down is doubled. Doubling the velocity
quadruples the erosive power and increases the quantity of soil that can be transported by
about 32 times and size of the particles that can be transported by about 64 times.
c) Vegetation: Vegetation intercepts the rainfall and reduces the impact of raindrops. It also
decreases the velocity of runoff by obstructing the flow of water. The fibrous roots are also
effective in forming stable soil aggregates, which increases infiltration and reduces erosion.
d) Soil Properties: Soil properties that influence soil erodability by water may be grouped
into two types.
i. Those properties that influence the infiltration rate and permeability
ii. Those properties that resist the dispersion, splashing, abrasion and
transporting forces of rainfall and runoff.
The structure, texture, organic matter and moisture content of upper layers determine the
extent of erosion. Sandy soils are readily detachable but not readily transportable. Soils of
medium to high clay content have low infiltration capacities and they are readily transported
by water after they are dispersed, but their detachability is generally low.
e) Man and beast
Man and beast accelerates erosion by extensive farming and excessive grazing. Faulty
practices like cultivation on steep slopes, cultivation up and down the slope, felling and
burning of forests etc., leads to heavy erosion. Excessive grazing destroys all vegetation and
increases the erosion.
Estimation of soil loss by water erosion
Based on the mechanism and factors influencing soil erosion, a universal soil loss
equation (USLE) developed by Wischmeier (1959) is most useful for predicting soil loss due
to water erosion. It is an empirical equation and estimates average annual soil loss per unit
area as a function of major factors affecting sheet and rill erosion. It enables determination of
land management erosion rate relationships for a wide range of rainfall, soil slope and crop
and management conditions and to select alternative cropping and management combinations
that limit erosion rates to acceptable limits.
A= R x K x L x S x C x P
where,
A= predicted soil loss in t/ha/year
R= rainfall erosivity factor or index
K= soil erodibility factor
L= length of slope factor
S= slope steepness factor
C= soil cover and management factor and
P= erosion control factor

B. Wind erosion
Erosion of soil by the action of wind is known as wind erosion. It is a serious problem
on lands devoid of vegetation. It is more common in arid and semi-arid regions. It is
essentially a dry weather phenomenon stimulated by the soil moisture deficiency. The
process of wind erosion consists of three phases:
a. initiation of movement b. transportation and c. deposition.
About 33 m.ha in India is affected by wind erosion. This includes 23.49 m.ha of
desert and about 6.5 m.ha of coastal sands. The Thar Desert is formed mainly by blow in
sand.
Mechanism of wind erosion
Lifting and abrasive action of wind results in detachment of tiny soil particles from
the granules or clods. The impact of these rapidly moving particles dislodge other particles
from clods and aggregates. These dislodged particles are ready for movement. Movement of
soil particles in wind erosion is initiated when the pressure by the wind against the surface
soil grains overcomes the force of gravity on the grains. Minimum wind velocity necessary
for initiating the movement of most erodable soil particles (about 0.1 mm diameter) is about
16 km /hr at a height of 30.5 cm. Most practical limit under field conditions, where a mixture
of sizes of single grained material present is about 21 km/hr at a height of 30.5 cm.
In general movement of soil particles by wind takes place in three stages: saltation,
surface creep and suspension.
a. Saltation:
It is the first stage of movement of soil particles in a short series of
bounces or jumps along the ground surface. After being rolled by the wind, soil
particles suddenly leap almost vertically to form the initial stage of movement in
saltation. The size of soil particles moved by saltation is between 0.1 to 0.5 mm in
diameter. This process may account for 50 to 70% of the total movement by wind
erosion.
b. Surface creep:
Rolling and sliding of soil particles along the ground surface due to
impact of particles descending and hitting during saltation is called surface creep.
Movement of particles by surface creep causes an abrasive action of soil surface
leading to break down of non-erodable soil aggregates. Coarse particles longer than
0.5 to 2.0 mm diameter are moved by surface creep. This process may account for 5
to 25% of the total movement.
c. Suspension:
Movement of fine dust particles smaller than 0.1 mm diameter by
floating in the air is known as suspension. Soil particles carried in suspension are
deposited when the sedimentation force is greater than the force holding the
particles in suspension. This occurs with decrease in wind velocity. Suspension
usually may not account for more than 15% of total movement.

Soil & Water Conservation Techniques
Definition of soil conservation
Soil conservation is using and managing the land based on the capabilities of the land
itself involving application of the best management practices leading to profitable crop
production without land degradation.
Control of water erosion
Water erosion occurs simultaneously in two steps: detachment of soil particles by
falling raindrops and transportation of detached particles by flowing water. Hence preventing
the detachment of soil particles and their transportation can minimize water erosion.
Principles of water erosion control are….
- Maintenance of soil infiltration capacity
- Soil protection from rainfall
- Control of surface runoff and
- Safe disposal of surface runoff
For a sound soil conservation program every piece of land must be used in accordance with
the land capability classification.
Measures of water erosion control
1. Agronomic measures
2. Mechanical measures (Engineering measures)
3. Agrostological measures
AGRONOMIC MEASURES OF SOIL CONSERVATION
In soil and water conservation programs agronomic measures have to be considered
in co-ordination with others for their effectiveness. These measures are effective in low
rainfall areas particularly in fairly erosion resistant soils having gentle slope (< 2 %).
The different agronomic measures include
1. Land preparation
2. Contour cultivation
3. Choice of crops
4. Strip cropping
5. Crop rotation / cropping systems
6. Cover crops
7. Mulching
8. Application of manures and fertilizers
9. Application of chemicals
a) Land preparation: Land preparation including post-harvest tillage influence intake of
water, obstruction to surface flow and consequently the rate of erosion. Deep ploughing or
chiseling has been found effective in reducing erosion. Rough cloddy surface is also effective
in reducing erosion.
b) Contour cultivation (Contour farming): A line joining the points of equal elevation is
called contour. All the cultural practices such as ploughing, sowing, inter-cultivation etc.
done across the slope reduce soil and water loss. By ploughing and sowing across the slope,

each ridge of plough furrow and each row of the crop act as obstruction to the runoff and
provide more time for water to enter into the soil leading to reduced soil and water loss.
c) Choice of crops: Row crops or tall growing crops such as sorghum, maize, pearl millet
etc. are not effective in conserving soil as they expose majority of the soil and hence they are
known as erosion permitting crops. Whereas close growing crops such as cowpea, groundnut,
green gram, black gram etc., which protect soil are known as erosion resisting crops as they
are very effective in reducing soil loss by minimizing the impact of rain drop and acting as
obstruction to runoff.
d) Strip cropping: It is a system of growing of few rows of erosion resisting crops and
erosion permitting crops in alternate strips on contour (across the slope) with the objective of
breaking long slopes to prevent soil loss and runoff. Close growing erosion resisting crops
reduce the transporting and eroding power of water by obstructing runoff and filtering
sediment from runoff to retain in the field. The width of the erosion permitting and erosion
resisting crops vary as per the slope of the field. The strip cropping resembles the
intercropping.
With increase in per cent slope of the soil, the width of erosion permitting and erosion
resisting crops decreases. The normal ratio between the erosion resisting crops and
erosion permitting crops is 1: 3.
The strip cropping is divided into four types as follows
i) Contour strip cropping: The erosion permitting crops and erosion resisting crops are
grown in alternate strips along the contours.
ii) Field strip cropping: Alternate strips of erosion permitting crops and erosion resisting
crops are raised across the general slope not necessarily on exact contour
iii) Wind strip cropping: Strip cropping of erosion permitting and erosion resisting crops
across the direction of the most prevailing wind irrespective of the contour.
iv) Buffer strip cropping: this type of strip cropping is practiced in areas having steep slopes
and badly eroded soils where strips of permanent cover crops or perennial legumes or
grasses or shrubs are alternated with field crops.
The strip cropping is simple, cheap and effective soil conservation practice and can
be adopted by the farmers.
e) Crop rotation / cropping system: Mono-cropping of erosion permitting crops accelerates
soil and water loss year after year. Intercropping of erosion permitting crops and erosion
resisting crops or their rotation has been found effective for reducing soil and water loss.
Inclusion of legumes like lucerne in crop rotation reduces soil loss even in soils having
13% slopes.
f) Cover crops: Good grounds cover by canopy gives the protection to the land like an
umbrella and minimize soil erosion. Besides conserving soil and moisture, the cover crops
hold those soluble nutrients, which are lost by leaching. The third advantage of the cover
crops is the addition of organic matter. The legumes provide better cover and better
protection. Among the legumes cowpea has been found to produce maximum canopy
followed by horsegram, green gram, black gram and dhaincha.
g) Mulching: Mulching of soil with available plant residues reduce soil loss considerably by
protecting the soil from direct impact of raindrop and reducing the sediment carried with
runoff .A minimum plant residue cover of 30 per cent is necessary to keep runoff and soil

loss within the acceptable limits. Vertical mulching also reduce soil loss particularly in
vertisols by increasing infiltration.
h) Application of manures and fertilizers : Organic manures besides supplying nutrients
improve soil physical conditions thereby reduce soil loss. Fertilizers improve vegetative
canopy, which aid in erosion control.
i) Use of chemicals: Breakdown of aggregates by the falling raindrops is the main cause of
detachment of soil particles. Soils with stable aggregates resist breakdown and thus resist
erosion. Aggregate stability can be increased by spraying chemicals like poly vinyl alcohol
@ 480 kg/ha (rate will depend on the type of soil). Soils treated with bitumen increase
water stable aggregates and infiltration capacity of the soil.
MECHANICAL MEASURES (ENGINEERING MEASURES)
The basic principle are: (i) shaping the land surface manually or with implements in
such a way as to reduce the velocity of runoff, (ii) to allow more time for rainfall to stand on
soil surface, and (iii) to facilitate more infiltration of rainfall into soil layers.
Choice of any particular method under a given situation is influenced by rainfall
characters, soil type, crops, sowing methods and slope of land.
(i) Basin listing: Formation of small depressions (basins) of 10–15 cm depth and 10–15 cm
width at regular intervals using an implement called basin lister. The small basins collect
rainfall and improve its storage. It is usually done before sowing. It is suitable for all soil
types and crops.
(ii) Bunding: Formation of narrow based or broad based bunds across slope at suitable
intervals depending on slope of field. The bunds check the free flow of runoff water,
impound the rainwater in the inter-bund space, increase its infiltration and improve soil
moisture storage. Leveling of inter-bund space is essential to ensure uniform spread of
water and avoid water stagnation in patches. It can be classified into three types:
(a) Contour bunding: Bunds of 1 m basal width, 0.5 m top width and 0.5 m height are
formed along the contour. The distance between two contour bunds depends on slope. The
inter-bund surface is leveled and used for cropping. It is suitable for deep red soils with
slope less than 1%. It is not suitable for heavy black soils with low infiltration where
bunds tend to develop cracks on drying. Contour bunds are permanent structures and
require technical assistance and heavy investment.
(b) Graded/field bunding: Bunds of 30-45 cm basal width, and 15-20 cm height are
formed across slope at suitable intervals of 20-30 m depending on slope. The inter-bund
area is leveled and cropped. It is suitable for medium deep-to-deep red soils with slopes up
to 1%. It is not suitable for black soils due to susceptibility to cracking and breaching.
Bunds can be maintained for 2-3 seasons with reshaping as and when required.
(c) Compartmental bunding: Small bunds of 15 cm width and 15 cm height are formed in
both directions (along and across slope) to divide the field into small basins or
compartments of 40 sq. m. size (8 × 5 m). It is suitable for red soils and black soils with a
slope of 0.5-1%. The bunds can be formed before sowing or immediately after sowing
with local wooden plough. It is highly suitable for broadcast sown crops. CRIDA has
recommended this method as the best in situ soil moisture conservation measure for
Kovilpatti region of Tamil Nadu. Maize, sunflower, sorghum performs well in this type of
bunding.

(iii) Ridges and furrows: Furrows of 30-45 cm width and 15-20 cm height are formed across
slope. The furrows guide runoff water safely when rainfall intensity is high and avoid
water stagnation. They collect and store water when rainfall intensity is less. It is suitable
for medium deep todeep black soils and deep red soils. It can be practiced in wide row
spaced crops like cotton, maize, chillies, tomato etc. It is not suitable for shallow red soils,
shallow black soils and sandy/ gravelly soils. It is not suitable for broadcast sown crops
and for crops sown at closer row spacing less than 30 cm. Since furrows are formed
usually before sowing, sowing by dibbling or planting alone is possible. Tie ridging is a
modification of the above system of ridges and furrows where in the ridges are connected
or tied by a small bund at 2–3 m interval along the furrows. Random tie ridging is another
modification where discontinuous furrows of 20–25 cm width, 45–60 cm length and 15
cm depth are formed between clumps or hills of crops at the time of weeding. Yet another
modification of ridges and furrows method is the practice of sowing in lines on flat beds
and formation of furrows between crop rows at 25–30 DAS. This enables sowing behind
plough or through seed drill.
(iv) Broad Bed Furrow (BBF): Here beds of 1.5 m width, 15 cm height and convenient
length are formed, separated by furrows of 30 cm width and 15 cm depth. Crops are sown
on the beds at required intervals. It is suitable for heavy black soils and deep red soils. The
furrows have a gradient of 0.6%. Broad bed furrow has many advantages over other
methods.
• It can accommodate a wide range of crop geometry i.e., close as well as wide row spacing.
• It is suitable for both sole cropping and intercropping systems.
• Furrows serve to safely guide runoff water in the early part of rainy season and store
rainwater in the later stages.
• Sowing can be done with seed drills.
• It can be formed by bullock drawn or tractor drawn implements. Bed former cum seed drill
enables BBF formation and sowing simultaneously, thus reducing the delay between
rainfall receipts and sowing.
(v) Dead furrow- At the time of sowing or immediately after sowing, deep furrows of 20 cm
depth is formed at intervals of 6–8 rows of crops. No crop is raised in the furrow. Sowing
and furrowing are done across slope. It can be done with wooden plough in both black and
red soils.
AGROSTOLOGICAL METHODS
The use of grasses to control soil erosion, reduce run off and improve soil moisture
storage constitutes the agrostological method. Grasses with their close canopy cover over soil
surface and profuse root system, which binds soil particles, provide excellent protection
against runoff and erosion. The following are the various agrostological methods of in situ
moisture conservation.
(i) Pastures/grass lands: Raising perennial grasses to establish pastures or grass lands is
recommended for shallow gravelly, eroded, degraded soils. Grass canopy intercepts
rainfall, reduces splash erosion, checks runoff and improves soil moisture storage from
rainfall.
(ii) Strip cropping with grasses: Alternate strips of grasses and annual field crops arranged
across slope check runoff and erosion and help in increasing moisture storage in soil.

(iii) Ley farming: It is the practice of growing fodder grasses and legumes and annual crops
in rotation. Grasses and legumes like Cenchrus, styloare grown for 3–5 years and followed
by annual crops like sorghum for 2 year. When the field is under grasses or legumes, soil
moisture conservation is improved.
(iv) Vegetative barriers: Vegetative barrier consists of one or two rows of perennial grasses
established at suitable interval across the slope and along the contour. It serves as a block
to free runoff and soil transport. Vetiver, Cenchrusetc., are suitable grasses. Vetiver can be
planted in rows at intervals of 40 m in 0.5% slope. Plough furrows are opened with disc
plough first before commencement of monsoon. 5–8 cm deep holes are formed at 20 cm
interval and two slips per hole are planted in the beginning of rainy season. The soil
around the roots is compacted. Vetiver barriers check runoff and prevent soil erosion.
While they retain the soil, they allow excess runoff to flow through their canopy without
soil loss. It is adapted to drought and requires less care for maintenance. It does not exhibit
any border effect on crops in adjacent rows. It allows uniform spread of water to lower
area in the field resulting in uniform plant stand thus increasing yield of a crop by 10–
15%. It facilitates better storage of soil moisture. If fodder grasses like Cenchrus
glaucusor marvel grass are used, fodder can also be harvested and given to the animal.
Vegetative barriers are best suited for black soil. Unlike contour bunding, which gives way
due to development of crack in summer in black soils, vegetative barriers do not allow
such phenomenon in black soil. Hence, the vegetative barriers can be effectively
maintained in black soil for 4–5 years. After 4–5 years, replanting material can also be had
from the old barrier by ‘quartering’.
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Drought; Types, effect of water deficit
5
Drought; Types, effect of water deficit on physio-morphological
characteristics of the plants
5.1 Introduction
Low rainfall or failure of monsoon rain is a recurring feature in India. This has been
responsible for droughts and famines. The word drought generally denotes scarcity of water
in a region. However, aridity and drought are due to insufficient water, aridity is a permanent
climatic feature and is the culmination of a number of long-term processes. However, drought
is a temporary condition that occurs for a short period due to deficient precipitation for
vegetation, river flow, water supply and human consumption. Drought is due to anomaly in
atmospheric circulation.
Aridity Vs. Drought
Particulars Aridity Drought
Duration Permanent feature Temporary condition of
scarcity of varying duration
Factors Culmination of many long term
processes , considers all climatic
features
Caused by deficient rainfall
Aspect described Description of Climate Description of Water
availability
5.2 Definition of drought
There is no universally accepted definition for drought.
 Early workers defined drought as prolonged period without rainfall.
 According to Ramdas (1960) drought is a situation when the actual seasonal rainfall is
deficient by more than twice the mean deviation.
 American Meteorological Society defined drought as a period of abnormally dry
weather sufficiently prolonged for lack of water to cause a severe hydrological
imbalance in the area affected.
 Prolonged deficiencies of soil moisture adversely affect crop growth indicating
incidence of agricultural drought. It is the result of imbalance between soil moisture and
evapo-transpiration needs of an area over a fairly long period so as to cause damage to
standing crops and to reduce the yields.
 The irrigation commission of India defines drought as a situation occurring in any
area where the annual rainfall is less than 75% of normal rainfall.
Criteria of Drought:
 NCA (1976) Agricultural drought as an occasion when at least four consecutive
weeks receive rainfall half of the normal (normal rainfall being 5 mm or more) during

the kharif crop season
 Drought areas: Regions which experienced drought in more than 20 per cent of years
 Chronic drought areas: Regions which experienced drought in more than 40 per cent
of the years
 Drought free period: When cumulative AE curve is above cumulative PE/2 curve
 Moderate drought period: When cumulative AE curve lies b/w cumulative PE/2 and
PE/4 curves.
 Severe drought period: When cumulative AE curve is below cumulative PE/4 curve
Annawary system:
Crop condition assessed through visual estimates
1. Production above 75 % of normal: No drought
2. Production 50 to 75 % of normal: Moderate drought
3. Production 25 to 50 % of normal: Severe drought
4. Production less than 25 % of normal: Disastrous drought
5.3 Classification of drought
Drought can be classified based on duration, nature of users, time of occurrence and
using some specific terms.
5.3.1 Based on duration
a. Permanent drought: This is characteristic of the desert climate where sparse
vegetation growing is adapted to drought and agriculture is possible only by
irrigation during entire crop season.
b. Seasonal drought: This is found in climates with well defined rainy and dry
seasons. Most of the arid and semiarid zones fall in this category. Duration of the crop
varieties and planting dates should be such that the growing season should fall
within rainy season.
c. Contingent drought: This involves an abnormal failure of rainfall. It may occur
almost anywhere especially in most parts of humid or sub humid climates. It is
usually brief, irregular and generally affects only a small area.
d. Invisible drought: This can occur even when there is frequent rain in an area.
When rainfall is inadequate to meet the evapo-transpiration losses, the result is
borderline water deficiency in soil resulting in less than optimum yield. This occurs
usually in humid regions.
5.3.2 Based on relevance to the users (National Commission on Agriculture,1976)
a) Meteorological drought: It is defined as a condition, where the annual precipitation is
less than the normal over an area for prolonged period (month, season or year).
b)Atmospheric drought: It is due to low air humidity, frequently accompanied by hot dry
winds. It may occur even under conditions of adequate available soil moisture. It refers to a
condition when plants show wilting symptoms during the hot part of the day when

transpiration exceeds absorption temporarily for a short period. When absorption keeps pace
with transpiration the plants revive. (Mid day wilt).
c) Hydrological drought: Meteorological drought, when prolonged results in hydrological
drought with depletion of surface water and consequent drying of reservoirs, tanks etc. It
results in deficiency of water for all sectors using water. This is based on water balance and
how it affects irrigation as a whole for bringing crops to maturity.
d)Agricultural drought (soil drought): It is the result of soil moisture stress due to
imbalance between available soil moisture and evapotranspiration of a crop. It is usually
gradual and progressive. Plants can therefore, adjust at least partly, to the increased soil
moisture stress. This situation arises because of scanty precipitation or its uneven distribution
in both space and time.
Relevant definition of agricultural drought appears to be a period of dryness during
the crop season, sufficiently prolonged to adversely affect the yield. The extent of yield loss
depends on the crop growth stage and the degree of stress. It does not begin when the rain
ceases, but actually commences only when the plant roots are not able to obtain the soil
moisture rapidly enough to replace evapo-transpiration losses.
5.3.3 Based on time of occurrence
a) Early season drought: It occurs due to delay in onset of monsoon or due to long dry
spells after early sowing
b) Mid season drought: Occurs due to long gaps between two successive rains and stored
moisture becoming insufficient during the long dry spell.
c) Late season drought: Occurs due to early cessation of rainfall and crop water stress at
maturity stage.
5.3.4. Other terms to describe drought
a) Relative drought: The drought for one crop may not be a drought situation for another
crop. This is due to mismatch between soil moisture condition and crop selection. For eg. A
condition may be a drought situation for growing rice, but the same situation may not be a
drought for growing groundnut.
b) Physiological drought: Refers to a condition where crops are unable to absorb water from
soil even when water is available, due to the high osmotic pressure of soil solution due to
increased soil concentration, as in saline and alkaline soils. It is not due to deficit of water
supply.
5.5 Periodicity of drought
The Indian Meteorological Department examined the incidence of drought for the
period from 1871 to 1967, utilizing the monthly rainfall of 306 stations in the country. It was
seen that during 1877, 1899, 1918 and 1972 more than 40 per cent of the total area
experienced drought. General observation on the periodicity of drought in respect of different
meteorological sub divisions of India is given below.

Meteorological sub divisions Period of recurrence of drought
Assam Very rare, once in 15 years
West Bengal, MP, Konkan, Coastal AP, Kerala,
Bihar, Orissa
Once in 5 years
South interior Karnataka, Eastern UP, Gujarat,
Vidharbha, Rajasthan, Western UP, TN, Kashmir,
Rayalaseema and Telangana
Once in 3 years
Western Rajasthan Once in 2.5 years
5.6 Important causes for agricultural drought are
• Inadequate precipitation
• Erratic distribution
• Long dry spells in the monsoon
• Late onset of monsoon
• Early withdrawal of monsoon
• Lack of proper soil and crop management
5.7 Effect of drought/water deficit on physio-morphological characteristics of plants
Effect on water deficit on crop
a) Water relations: Alters the water status by its influence on absorption, translocation
and transpiration. The lag in absorption behind transpiration results in loss of turgor as
a result of increase in the atmospheric dryness.
b) Photosynthesis: Photosynthesis is reduced by moisture stress due to reduction in
Photosynthetic rate, chlorophyll content, leaf area and increase in assimilates
saturation in leaves (due to lack of translocation).
c) Respiration: Increase with mild drought but more serve drought lowers water content
and respiration.
d) Anatomical changes: Decrease in size of the cells and inter cellular spaces, thicker
cellwall, greater development of mechanical tissue. Stomata per unit leaf tend to
increase.
e) Metabolic reaction: All most all metabolic reactions are affected by water deficits.
f) Hormonal Relationships: The activity of growth promoting hormones like cytokinin,
gibberlic acid and indole acetic acid decreases and growth regulating hormone like
abscisic acid, ethylene, etc., increases.
g) Nutrition: The fixation, uptake and assimilation of nitrogen are affected. Since dry
matter production is considerably reduced, the uptake of NPK is reduced.
h) Growth and Development: Decrease in growth of leaves, stems and fruits.

Maturity is delayed if drought occurs before flowering while it advances if drought
occurs after flowering.
i) Reproduction and grain growth: Drought at flowering and grain development
determines the number of fruits and individual grain weight, respectively. Panicle
initiation in cereals is critical while drought at anthesis may lead to drying of pollen.
Drought at grain development reduces yield while vegetative and grain filling stages
are less sensitive to moisture stress.
j) Yield: The effect on yield depends hugely on what proportion of the total dry matter
is considered as useful material to be harvested. If it is aerial and underground parts,
effect of drought is as sensitive as total growth. When the yield consists of seeds as in
cereals, moisture stress at flowering is detrimental. When the yield is fiber or
chemicals where economic product is a small fraction of total dry matter moderate
stress on growth does not have adverse effect on yields.
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Crop adaptation and mitigation to drought
6 Crop adaptation and mitigation to drought
6.1 Crop Adaptations
The ability of crop to grow satisfactorily under water stress is called drought
adaptation. Adaptation is structural or functional modification in plants to survive and
reproduce in a particular environment.
Crops survive and grow under moisture stress conditions mainly by two ways: (i)
escaping drought and (ii) drought resistance (Fig. 6.1)
Fig. 6.1 Flow chart showing different mechanisms for overcoming moisture stress
6.1.1 Escaping Drought
Evading the period of drought is the simplest means of adaptation of plants to dry
conditions. Many short duration desert plants, (ephemerals), germinate with rains and mature
in five to six weeks. These plants have no mechanism for overcoming moisture stress and are,
therefore, are not drought resistant.
In cultivated crops, the ability of a cultivar to mature before the soil dries is the main
adaptation to growth in dry regions. However, only very few crops have such a short growing
season to be called as ephemerals. Certain varieties of pearl millet mature within 60 days
after sowing. Short duration pulses like cowpea, greengram, black gram can be included in
this category. In addition to earliness, they need drought resistance because there may be dry
spells within the crop period of 60 days. The disadvantage about breeding early varieties is
that yield is reduced with reduction in duration.

6.1.2 Drought Resistance
Plants can adopt to drought either by avoiding stress or by tolerating stress due to
different mechanisms. These mechanisms provide drought resistance.
i. Drought avoidance
A. Restricting transpiration (water
savers)
1. Early stomata closer
2. Increased photosynthetic efficiency
3. Low rates of cuticular respiration
4. Lipid deposition on foliage
5. Reduced leaf area
6. Morphology of leaf surface
7. Water storage in the plant
B. Accelerating water uptake (water
spenders)
1. Efficient root system
2. High root/shoot ratio
3. Increases osmotic potential
ii. Drought tolerance
A. Mitigating stress
1. Resistance to dehydration
2. Thick cuticle
3. Maintenance of high osmotic pressure
B. High tolerance
1. Metabolic strain
2. Plastic strain
6.1.3 Avoiding Stress
Stress avoidance is the ability to maintain a favorable water balance, and turgidity
even when exposed to drought conditions, thereby avoiding stress and its consequences. A
favorable water balance under drought conditions can be achieved either by: (i) conserving
water by restricting transpiration before or as soon as stress is experienced; or (ii)
accelerating water uptake sufficiently so as to replenish the lost water.
6.2 Strategies for drought management
The different strategies for drought management are discussed under the following
heads.
6.2.1 Adjusting the plant population: The plant population should be lesser in dryland
conditions than under irrigated conditions. The rectangular type of planting pattern should
always be followed under dryland conditions. Under dryland conditions whenever moisture
stress occurs due to prolonged dry spells, under limited moisture supply the adjustment of
plant population can be done by
a) Increasing the inter row distance: By adjusting more number of plants within

the row and increasing the distance between the rows reduces the competition
during any part of the growing period of the crop. Hence it is more suitable for
limited moisture supply conditions.
b) Increasing the intra row distance: Here the distance between plants is
increased by which plants grow luxuriantly from the beginning. There will be
competition for moisture during the reproductive period of the crop. Hence it is less
advantageous as compared to above under limited moisture supply.
6.2.2 Mid-season corrections: The contingent management practices done in the
standing crop to overcome the unfavorable soil moisture conditions due to
prolonged dry spells are known as mid-season conditions.
a) Thinning: This can be done by removing every alternate row or every third row which
will save the crop from failure by reducing the competition
b) Spraying: In crops like groundnut, castor, red gram, etc., during prolonged dry spells the
crop can saved by spraying water at weekly intervals or 2 per cent urea at week to 10 days
interval.
c) Ratooning: In crops like sorghum and bajra, ratooning can practiced as mid-season
correction measure after break of dry spell.
6.2.3 Mulching: It is a practice of spreading any covering material on soil surface to reduce
evaporation losses. The mulches will prolong the moisture availability in the soil and save the
crop during drought conditions.
6.2.4 Weed control: Weeds compete with crop for different growth resources ore seriously
under dryland conditions. The water requirement of most of the weeds is more than the crop
plants. Hence they compete more for soil moisture. Therefore the weed control especially
during early stages of crop growth reduces the impact of dry spell by soil moisture
conservation.
6.2.5 Water harvesting and lifesaving irrigation:
The collection of runoff water during peak periods of rainfall and storing in
different structures is known as water harvesting. The stored water can be used for
giving the life saving irrigation during prolonged dry spells.
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Water Harvesting
7 Water Harvesting
7.1 Meaning of water harvesting:
The process of runoff collection during periods of peak rainfall in storage tanks,
ponds etc., is known as water harvesting. It is a process of collection of runoff water from
treated or untreated land surfaces/ catchments or roof tops and storing it in an open farm pond
or closed water tanks/reservoirs or in the soil itself (in situ moisture storage) for irrigation or
drinking purposes. Runoff farming and rainwater harvesting agriculture are synonymous
terms, which imply that farming is done in dry areas by means of runoff from a catchment.
Runoff farming is basically a water harvesting system specially designed to provide
supplemental or lifesaving irrigation to crops, especially during periods of soil moisture
stress.
Collecting and storing water for subsequent use is known as water harvesting. It is a
method to induce, collect, store and conserve local surface runoff for agriculture in arid and
semiarid regions. All water harvesting systems have three components viz., the catchment
area, the storage facility and the command area. The catchment area is the part of the land
that contributes the rain water. The storage facility is a place where the runoff water is stored
from the time it is collected until it is used. The command area is where water is used.
Water harvesting is done both in arid and semi-arid regions with certain differences.
In arid regions, the collecting area or catchment area is substantially in higher proportion
compared to command area. Actually, the runoff is induced in catchment area in arid lands
whereas in semi-arid regions, runoff is not induced in catchment area, only the excess rainfall
is collected and stored. However, several methods of water harvesting are used both in arid
and semiarid regions.
Water harvesting (WH) is generally considered as a rudimentary form of irrigation.
The difference is that with WH the farmer’s has no control over timing. Runoff can only be
harvested when it rains. Water harvesting in its broadest sense will be defined as the
"collection of runoff for its productive use". Runoff may be harvested from roofs and ground
surfaces as well as from intermittent or ephemeral water courses. Water harvesting
techniques which harvest runoff from roofs or ground surfaces fall under the term ‘rainwater
harvesting’ while all systems which collect discharges from water courses are grouped under
the term ‘flood water harvesting’.
In regions where crops are grown entirely rainfed, a reduction of 50% in the seasonal
rainfall, for example, may result in a total crop failure. If, however, the available rain can be
concentrated on a smaller area, reasonable yields will be received. In a year of severe drought
there may be no runoff to collect, but an efficient water harvesting system will improve plant
growth in the majority of the years. Hence, collecting and storing rainwater for subsequent
use is called as ‘water harvesting’. It is a method to induce, collect, store and conserve local
surface runoff for arid and semi-arid regions. It is also known as ‘runoff farming’ in rainfed
areas.
7.2 Components and principles of water harvesting:
All water harvesting systems have three components viz., the catchment area, the
storage area and the command area. The catchment area (donor area) is the part of the land
that contributes the rainwater. The storage facility is a place where the runoff water is stored

Water Harvesting
from the time it is collected until it is used for human beings and their needs. The area in
which collected water is used is called command area (recipient area). The donor area is
generally not suitable for crop production.
Fig. Components of a water harvesting system
Water harvesting is a process of collection of
peak rainfall runoff water from treated or
untreated land surfaces / catchments / roof
tops and storing it in an open farm pond or
closed water tanks / reservoirs or in the soil
itself (in-situ moisture storage) for
agriculture or domestic purposes. In runoff
farming, a water harvesting system is
specially designed to provide supplemental
irrigation to crops, especially during periods
of soil moisture stress.
The aim of water harvesting is to mitigate the effects of temporal shortage of rain, so
called dry spells, groundwater recharge, risk minimizing in drought-prone areas, combating
desertification by tree plantation, to cover both household needs (for drinking, cooking,
sanitation, etc.) as well as for productive use (protective irrigation).
The implementation of water harvesting might, however, bring about a number of
drawbacks. The main disadvantages of rainwater harvesting technologies are mainly due
to the limited supply and uncertainty of rainfall. The others are:
1. Increased soil erosion when slopes are cleared for higher runoff rates.
2. Loss of habitat of flora and fauna on these slopes and depressions.
3. Upstream-downstream conflicts among the beneficiaries.
4. Competition among the farmers and the herders.
7.3 The importance of water harvesting can be summarised as:
1. In arid and semi-arid areas where rainfall is low and unfavourably distributed, water
harvesting makes farming possible on part of the land provided other production
factors are favourable.
2. It can provide additional water to supplement rainfall to increase and stabilize crop
production in dryland areas.
3. It can alleviate the risk associated with the unpredictability of rainfall in drought-
prone areas.
4. In remote areas (islands and deserts) where public water supply for domestic and
animal rearing is not available, inducing runoff from treated area and stored in a
reservoir/ cistern for later use is a common practice.
5. In islands and high hilly areas, due to limited extent of fresh water aquifers, rainwater
harvesting is the most preferred source of water for domestic use.
6. The arid lands suffering from desertification, water harvesting would improve the
vegetative cover and help to halt the environmental degradation.
7. Water harvesting arrest decline in groundwater levels, to overcome the inadequacy of
surface water to meet our demands.
7.4 Water harvesting structures

Water Harvesting
At present most water harvesting structures are built under the holistic programme of
watershed development which includes:
 Roof top rainwater harvesting for domestic use;
 Creating surface water storages in the form of check dams, dug ponds for irrigation
and drinking;
 Recharging ground water through check dams, percolation tanks, sub-surface dykes to
augment water availability in wells, tube wells, hand pumps etc.;
 Soil conservation through afforestation, gully plugging, contour cropping, control
and regulation of grazing;
 Soil moisture conservation especially in rainfed hilly areas, through bench terracing,
contour bunding, khadins to suppress soil salinity;
 Improving cropping pattern, crop calendar etc. for enhancing farm income;
 Improving marketing facilities for farm produce;
 Providing additional livelihood options such as dairy farming, poultry farming, bee
keeping, sericulture etc,;
 Promoting social forestry to meet the fuel wood requirement where alternative
sources of fuel are not feasible.
7.5 Techniques of Inducing Runoff
Rainwater harvesting is possible even in areas with as little as 50 to 80 mm average
annual rainfall. Ancient desert dwellers harvested rain by redirecting the water running down
the slopes into fields or cisterns (storage structures). This small amount of runoff collected
over large area may be useful for supplying water to small villages, households, cattle etc.
For collection of higher amount of rainfall, runoff is induced either by inter-plot water
harvesting or by land alteration or by surface chemical treatment.
a) Land alterations:
Land smoothing reduce surface depression storage and infiltration losses. Clearing away
rocks and vegetation and compacting the soil surface can increase runoff. However, land
alteration may lead to soil erosion except where slope is reduced. When erosion is not excessive
and low cost hill side land is available, land alteration can be very economical way to harvest
rainwater in arid lands.
b) Surface chemical treatment:
A promising method for harvesting rainwater is to treat soils with chemicals that fill
pores or make soil repellent to water. Some materials used for this purpose are sodium salts
of silicon, latexes, asphalt and paraffin wax. Surface treatment of soil with bitumen and
asphalt is effective for inducement of runoff. Most of the treatments for inducing runoff are
location-specific and depends on importance of runoff collection and cost associated with the
treatment.
c) Soil cover:
Surface modifications may be required to get more runoff. Runoff may be induced by
using low density polyethylene sheets, butyl rubber, asphalt and fibre glass, compacting
surface or spreading sodic soil on surface as soil cover. In cropping systems, crop is sown in
narrow strips between wide intervals that are ridged as artificial miniature watersheds.
Compacting the soil surface is the cheapest way to induce runoff in rainfed areas.
7.6 Techniques of Rainwater Harvesting:

Water Harvesting
The water harvesting techniques are classified into five groups. These are sketched as
given below:
Water harvesting is done both in arid and semi-arid regions with certain differences.
In arid regions, the collecting area or catchment area is substantially in higher proportion
compared to command area. Actually, the runoff is induced in catchment area in arid lands
whereas in semi-arid regions, runoff is not induced in catchment area, only the excess rainfall
is collected and stored. However, several methods of water harvesting are used both in arid
and semi-arid regions.
The different methods of water harvesting that are followed in arid and semi-arid
regions are discussed below.
7.6.1 Arid Regions
The catchment area should provide enough water to mature the crop, and the type of
farming practiced must make the best use of water. In general, perennial crops are suitable as
they have deep root systems that can use runoff water stored deep in the soil which is not lost
through evaporation.
a) Runoff farming:
Ancient runoff farms in the Negev desert (Israel) had several cultivated fields fed by
water from watersheds of 10 to 50 ha. The watersheds were divided into small catchment
areas of 1 to 3 ha that allowed runoff water to be collected in easily catchment channels on
the hill sides and were small enough to prevent uncontrollable amount of water. The channels
that led the water to cultivated fields were terraced and had stone spillways so that surplus
water in one field could be led to lower ones. Farmers constructed small check dams with
rocks across the small gullies and guided the water to fields.
The farmers of Madhya Pradesh (Rainfed
central India) have developed a unique and
indigenous rainwater management system based
on water harvesting and runoff farming, locally

Water Harvesting
known as ‘Haveli’. In this system, rainwater is harvested (0.2–1.2 m depth) in the field
during monsoon (June–September) by constructing embankments along the field boundary.
The farmers allow rainwater to flow from one field to another. The impounded water is then
drained out from the field during September–October. The winter crops (wheat, pea, lentil
and chickpea) are grown which utilize the stored moisture seeped in the soil profile. ‘Haveli’
fields contribute 4–6 mm rainwater per day for 90–100 days in the rainy season,
corresponding to 40–60 cm conserved moisture in upper soil profile. The drained water from
‘Haveli’ fields is also used for irrigation by the adjacent farmers to grow rice. It helps greatly
to control weeds, soil moisture conservation and ground water recharge.
b) Water spreading:
In arid areas, the limited rainfall is received as short intense storms. Water swiftly
drains into gullies and then flows towards the sea. Water is lost to the region and floods
caused by this sudden runoff can be devastating often to areas otherwise untouched by the
storm. Water spreading is a simple irrigation method for use in such a situation. Flood waters
are deliberately diverted from their natural courses and spread over adjacent plains. The water
is diverted or retarded by ditches, dikes or small dams. The wet flood plains or valley floods
are used to grow crops. Sorghum and millets are the most common crops.
The major characteristic of water spreading bunds is that, as their name implies, they
are intended to spread water, and not to impound it. They are usually used to spread
floodwater which has either been diverted from a watercourse or has naturally spilled onto
the floodplain. The earthen bunds slow down the flow of floodwater and spread it over the
land to be cultivated, thus allowing it to infiltrate. The dikes can be constructed with a tractor
and mouldboard plough or with a road grader.
Fig.
Water spreading system in
Pakistan to divert excess flood
water for agricultural use.
If a site received <200 mm annual
precipitation or <100-130 mm
during the growing season, it
would typically not produce
enough runoff to justify
installation of a water spreader.
c) Micro-catchments (Negarim):
A plant can grow in a region with too little rainfall for its survival if a rainwater
catchment basin is built around it. At the lowest point within each micro-catchment, a basin is
dug about 40 cm deep and a tree is planted in it. The basin stores the runoff from micro-
catchment. In Africa these are used for cultivation of sorghum, maize and millets.
Appropriate for tree planting in situations where land is uneven or only a few trees are
planted. Widely used micro-catchments are contour ridges, semi-circular and trapezoid bunds
and small runoff basins. The main limitation is that it is not easily mechanised therefore
limited to small scale. Not easy to cultivate between tree lines.
Dive
C

Water Harvesting
Fig.
Negarim micro-catchment for trees
It works great with rainfall rates
starting from 150 mm/year and they are
applied on slopes upto 15%.
Macro-catchments having runoff water collected from relatively large natural
catchments. Generally these catchments are located outside the farm boundaries where
individual farmers have little or no control over them. Percolation tank is an example of
macro-catchment WH system.
d) Traditional water harvesting systems:
Tanka, Virda, Kunds, Nadi, Johad and khadin are the important traditional water
harvesting systems of Rajasthan. The maximum conservation of water is in the form of lakes.
The GOI, reconstructed these traditional WH systems under MGNREGA all over the country.
Tanka is the most prevailing rainwater harvesting
structure in Indian Thar desert. It is an underground circular
tank or cistern constructed for collection and storage of runoff
water from natural catchment or artificially prepared clean
catchment or from a roof top. The vertical walls are lined with
stone masonry or cement concrete and the base with 10 cm
thick concrete. The capacity of the tank ranges from 1,000 to
6,00,000 L. A traditional tanka constructed with lime plaster
and thatched with bushes has a life span of 3–4 years. CAZRI
(Jodhpur) has designed an improved tanka (life-span 25 years)
of 21,000 L capacity which gets filled with an annual rainfall of
125 mm. The catchment area needed for this capacity is 700 m².
Virdas are shallow holes which are made in the sands of
dry riverbeds and lakes for collecting drinking water. These are
found all over the Banni grasslands, a part of the great Rann of
Kutch in Gujarat. The topography of the area is undulating,
with depressions on the ground. In virdas, the sweet freshwater
remains in the upper layer from which the water is collected,
and the saline water remains below the freshwater zone because
of its higher density and, hence, it is theoretically possible to
keep the harvested sweet rainwater stored to float over the
denser saline water.
With this knowledge, Maldharis (local nomadic people)
first developed this unique structure in the Rann of Kutch,
which is essentially like a well in a tank. A group of thorny
bush branches enclosed a virda to ward off animals.

Water Harvesting
Kunds were more prevalent in the western arid regions
of Rajasthan, and in areas where the limited groundwater
available is moderate to highly saline. Usually it is constructed
with local materials or cement. The kund consists of a saucer-
shaped catchment area with a gentle slope towards the centre
where a tank is situated. Openings or inlets for water to go into
the tank are usually guarded by a wire mesh to prevent the entry
of floating debris, birds and reptiles. The top is usually covered
with a lid from where water can be drawn out with a bucket.
An area receiving rainfall of 25 mm/annum, a kund with
a catchment of 100 km² could easily collect 10,000 L of
water. Even if we assume that only 40 - 50% of rain will turn
into runoff, a kund can still store 0.1 million litres of water. The
catchment size of kunds varies from about 20 m² to 2 ha
depending on the runoff needed, water use and the availability
of spare land.
Nadi or dugout village pond (Pokhar) is constructed for
storing water from natural catchments. It is more prevalent in
western Rajasthan. The depth and capacity of the nadi may
varies from1.5 to 12 meters and 400 m3
to 70,000 m3
,
respectively. A large amount of sandy sediments were regularly
deposited in them, resulting in quick siltation. The water is
muddy and dirty which is unfit for human consumption.
However, due to water scarcity peoples used this water for all
purposes.
Khadin is unique land use system of Thar desert where
in runoff water from rocky catchments are collected in valley
plains during rainy season. It is practised where rock
catchments and valley plains occur in proximity to sandy hills.
This old water harvesting system was first practised by the
Paliwal Brahmins of Jaisalmer, western Rajasthan in the 15th
century.
The standing water in a khadin assists in continuous
groundwater recharge. Its main feature is a very long (100–300
m) earthen embankment built across the lower hill slopes lying
below gravelly uplands. Sluices and spillways allow excess
water to drain off. Crops are grown in the winter season after
water is receded in shallow pond on the residual soil moisture.
At least one crop is cultivated even in the arid region on khadin
bed. The soils in khadin are extremely fertile due to frequent
deposition of fine sediment.

Water Harvesting
Johads are crescent-shaped small earthen bunds which
is built across a slopping catchment/ seasonal channels that
capture and conserve rainwater, improving percolation and
groundwater recharge. Unlike a normal dam, the rainwater is
collected during monsoon and allowed to percolate into the soil.
Since 1984, a total of 8600 johads have been built in
1086 villages of Alwar district in Rajasthan, covering 6500 km²
area under the leadership of Tarun Bharat Sangh and its leader
Rajendra Singh, the Water Man of Rajasthan. These johads
have helped the farming communities from abject poverty to
prosperity, a miraculous transformation. This has resulted in the
shallow aquifer recharge in groundwater bringing up the water
table from about 100–120 meter depth to 3–13 meter at present.
The area under single and double cropping was 11% and 3%,
which was increased to 70% and 50%, respectively. The forest
cover, which used to be around 7%, increased to 40% through
agro-forestry and social forestry, providing sufficient fuel wood
and sequestering carbon from the atmosphere.
7.6.2 Semi-arid Regions
Water harvesting techniques followed in semi-arid areas are numerous and also
ancient. These are-
a) Dug Wells:
Hand dug wells have been used to collect and store underground water and this water
is lifted for irrigation. The quality of water is generally poor due to dissolved salts.
b) Tanks:
Runoff water from hill sides and forests is collected on the plains in tanks. The
traditional tank system has following components viz., catchment area, storage tank, tank
bund, sluice, spillway and command area. The runoff water from catchment area is collected
and stored in storage tank on the plains with the help of a bund. To avoid the breaching of
tank bund, spillways are provided at one or both the ends of the tank bund to dispose of
excess water. The sluice is provided in the central area of the tank bund to allow controlled
flow of water into the command area. Water from the tanks is used to irrigate the command
area by gravity flow. The command area of many tanks ranges from 25 to 100 ha. Unlike
wells, the quality of water is good in tanks.
c) Percolation Tanks:
Flowing rivulets or big gullies are obstructed and
water is ponded. Water from the ponds percolates into
the soil and raises the water table of the region. The
primary purpose of percolation tank is to recharge
groundwater. A strict regulation on the silt load entering
the downstream reservoirs is an additional advantage of
percolation tanks. The improved water level in the wells
lower down the percolation tanks are used for
supplemental irrigation.

Water Harvesting
d) Farm Ponds:
A portion of the excess runoff water after allowing maximum in-situ moisture
conservation is collected in farm ponds. As far as possible, the pond should be location in the
lower patches of the field to facilitate better storage and less seepage losses. The size of the
farm should be worked out on the basis of annual rainfall, probable runoff and catchment
area. Generally, 10-20% of the seasonal rainfall is considered as runoff in medium black
soils. A farm pond of 150 m³ capacity with side slopes of 1.5:1 is sufficient for one ha of
catchments area in black soils.
Depending upon their construction and suitability to different topographic conditions
farm ponds are classified as:
 Excavated farm ponds : Suitable for flat topography
 Embankment ponds : Suitable for hilly terrains and
 Excavated cum embankment ponds
There are three types of excavated farm ponds – square, rectangular and circular.
Circular ponds have high water storage capacity. Farm ponds of size 100 to 300 m3
may be
dug to store 30% of runoff. The problem associated with farm ponds in red soils is high
seepage loss. This can be reduced by lining walls. Some of the traditional methods for
seepage control are the use of bentonite, soil dispersants and soil-cement mixture. Bentonite
has excellent sealing properties if kept continuously wet, but cracks develop when dried.
Soil-cement mixture can be used. A soil-cement lining of 100 mm thickness reduces
seepage losses up to 100 per cent. The pit lined continuously develops cracks but no cracks
develop when applied in blocks. The other alternative sealant for alfisols is a mixture of red
and black soil in the ratio of 1:2.
Fig. Typical layout of a farm pond
In arid and semi-arid regions, rains are sometimes received in heavy down pours resulting
in runoff. The runoff event ranges from 4 to 8 during the rainy season in arid and semi-arid
region. The percentage of runoff ranges from 10 to 30% of total rainfall. The size of the farm

Water Harvesting
pond depends on the rainfall, slope of the soil and catchment area. The dimensions may be in the
range of 10×10 m × 2.5 to 15 × 15 m × 3.5 m. The side slope 1.5:1 is considered sufficient. A silt
trap is constructed with a width of slightly higher than the water course and depth of 0.5 to 1 m
and with side slope of 1.5:1.
The different types of lining materials are soil-cement, red and black soils, cement-
concrete, bricks, kadapa slabs, stone pitching, polythene sheet etc. In alluvial sandy loam to
loamy sand soils of Gujarat and red sandy loams soils of Bangalore, a soil + cement (8:1) mixture
is the best lining material.
Soil without sieving and cement in
6:1 ratio is very effective and cheap lining
material for red sandy loam soils. In laterite
silty clay loam soils of Ooty, medium black
soils of Kota, bitumen was effective. Clay
soil linings are generally the most
economical for farm ponds. Evaporation
losses can be reduced in farm ponds
especially in arid regions by rubber or
plastic floats. Farm pond lined with soil+cement (6:1 ratio)
e) Inter-row water harvesting (IRWH)
Under this system, furrows of about 30-40 cm width (15 cm deep) are alternated by ridges
of 60-70 cm).The furrows and ridges are formed with ridger at right angles to the slope. The
water collected from the ridge is stored in furrow and the crop is benefitted by high moisture. The
ridge may be left without ploughing while cultivation is done in the furrow only. The ridge
provides partial shading of the furrow for 6 to 7 hours a day and reduces evaporation by 25-35%
immediately after rain. It is, particularly, suitable for heavy textured soils. In light soils, crops are
grown in furrows whereas in heavy soils, planting is usually on ridges to eliminate the problem of
water-logging. In this system, the raindrops absorbed where it falls and does not flow out of the
field. Generally it is practiced in areas having annual rainfall between 200-300 mm.
Raised and sunken bed system is the traditional system followed by the farmers of
Chhattisgarh. Rice is grown in the sunken bed and soybean is sown on the raised bed, thereby
meeting the water requirement of both the crops.
f) Inter-plot water harvesting (IPWH):
In this method, harvested water is diverted to the cropped area. It is suitable where
rainfall is scanty (<500 mm) and even there is difficulty of harvesting a single crop. In this
technique, runoff water is made available to cropped plots from adjacent bare plots either on one
side or both sides. Adjacent plots are given certain slope to augment runoff towards cropped plot
for improving profile moisture storage. Catchments with strips of 0.75 m width on either side of
3.0 m wide levelled area are desirable. Catchment to cultivated area ratio of 0.5 could be
optimum for most crops.

Water Harvesting
Slopes on both sides of cropped area appear to be more appropriate for arid-fruit trees.
The 1:1 cropped to non-cropped area on both side slopes gave better results followed by 1:1 and
1:2 one side slope
.
Fig. Inter-plot or micro-plot water harvesting for field crops
g) Broad Bed & Furrows (BBF):
When seedbed is made into wide beds alternated with furrows is called BBF. This
practice has been recommended by ICRISAT for vertisols or black soils in high rainfall areas
(>750 mm). The system involves creation of 90-150 cm wide, 15-20 cm high raised beds with 0.3
to 0.5% grades. The beds are separated by 50 cm wide furrows that drain into grassed waterways.
The beds are stable for 2 to 4 years and conveniently adapted to planting of upland crops in rows
spaced at 30, 45, 75 or 150 cm. The system tends to conserve soil, rainwater in-situ and improves
crop yields and sustainability.
Advantages of Broad Bed & Furrow
 It helps in moisture storage.
 Safely dispose-off surplus surface runoff without causing erosion.
 Provide better drainage facilities.
 Facilitate dry seeding.
 It can accommodate a wide range of crop geometry i.e. close as well as wide row spacing.
 It is suitable for both sole cropping and intercropping systems.
 Sowing can be done with seed drills.
7.7 Storage, management and use of harvested rainwater:
Storage is an important and integral part of any water harvesting system. In run-off
farming, the storage reservoir will be the soil itself. But where water is to be used for
domestic/supplemental irrigation purposes, a storage facility of some kind would be provided.
There are three basic means of storing harvested water viz., excavated pits/ponds, masonry tanks
and closed plastic storage bags. At on-farm level, three approaches are being adopted in
rainwater management viz.,
a) Absorbed where it falls and does not flow out of the field.

Water Harvesting
a) Harvesting rainwater into dug out structures like farm ponds. To check the seepage
losses from these ponds several sealing materials are used.
b) Recycling of stored water to donor area as supplemental /life-saving irrigation.
Supplemental / life-saving / protective irrigation:
The runoff collected from different water storage structures is of immense use for
protecting the dryland crops from soil moisture stress during prolonged dry spells. In dry
areas, water, not land is the most limiting resource for crop production. Maximizing the water
productivity but not the yield per unit land is the better strategy for dry farming areas.
Supplemental irrigation is a highly efficient practice for increasing productively of crops in
arid regions. The response to supplemental irrigation varies with crops, time, depth & method
of water and fertilizer application. Irrespective of the stage of crop, irrigation is scheduled
when soil moisture approaches PWP to save the crop. This is called life-saving irrigation.
The benefit of supplemental irrigation last for one week.
a) Quantity of irrigation water:
Crops differ in responding to amount of irrigation water by supplemented irrigation
during dry spell.
Crops Soil type Critical stage Quantity of water (mm) Methods of
application
Groundnut Alfisols Pod development 10 mm Sprinkler / drip
Cotton Vertisols Boll formation 30 mm Sprinkler / drip
Chickpea Black soils Flowering 30-40 mm Sprinkler / drip
pigeonpea Black soils Pod development 20 mm Drip
Life-saving irrigation can be provided near the row, covering about 20% of the
cropped area, leaving 80% of inter-row zone. Pot watering, applying small quantity of water
(around 250 ml) manually to each hill, is highly useful either for sowing or for transplanting
in widely spaced crops like cotton, pigeonpea, castor, tomato, tobacco etc. Productivity of
harvested water can be increased by applying small quantity of water to large areas than
heavy irrigation to small area. If rains occur immediately after irrigation, there will be no
impact of irrigation and in black soil, it may reduce yield.
b) Time of irrigation:
Unlike in irrigated agriculture, the critical stage concept does not suit well, as dry
spell may reduce the growth and yield of crop at any stage. Vegetative stage is considered as,
non-critical stage in irrigated agriculture but in arid regions, dry spell during vegetative stage
prolongs the crop duration which may ultimately result in crop failure due to end season
drought. Death of seedlings also cause reduction in yield due to dry spell in vegetative stage,
therefore, the strategy for getting successful crop is providing small quality of water, if
available, at any stage if the dry spell is >10 days in light soils and 15 days in heavy soils.
When critical stage for irrigation is to be chosen e.g. for kharif sorghum the flowering
stage is most critical. In Tobacco, irrigation at 3 weeks before topping had the maximum pay
off. For wheat and barley CRI stage is most critical stage. Long duration crops with deeper
root systems that responded to higher levels of irrigation compared to short duration shallow
rooted crops. Hence, it is important to wet the active root profile for best results.
c) Method of irrigation:

Water Harvesting
Surface methods of irrigation like check basin, basin, and furrow methods are not
suitable for supplemental irrigation, mainly for three reasons: the rainfed lands are uneven,
conveyance losses may go upto 30% and limited amount of water available for irrigation.
Subsurface drip irrigation is very efficient for providing supplemental irrigation. The main
drawback of micro-irrigation system is high initial cost of the system. Pot watering is another
efficient method being used by the farmers for transplanting crops like tobacco, chilly,
tomato etc.
d) Economics of water harvesting:
Water harvesting and use of water for sowing and supplemental irrigation increase the
productivity of wheat and onion in mountainous watershed in Himachal Pradesh. The benefit-
cost ratio ranges from 0.41 to 1.33 for water harvesting structures of different sizes with an
estimated life of 25 and 40 years, respectively.
e) Water productivity:
The limited water productivity can be increased through timely sowing, use of
improved varieties, STCR based fertilizer application, timely weeding and efficient irrigation
system.
7.8 Efficient utilization of rainwater through soil management practices:
In rainfed agriculture, no other input can perhaps enhance the yield without
effectively tackling of the rainfall aberration related sub-optimal moisture availability by
managing both soil and rainwater.
The important practices are-
1. Avoiding and rectifying soil degradation
The major forms of soil degradation are water and wind erosion and deterioration of
both physical (crusting, compaction, waterlogging) and chemical (Loss of organic matter,
acidification, salinization, pollution etc.). Soil crusting and compaction in arable soils may be
rectified by cultivation, Increasing soil organic matter content by incorporating organic
manures and pond sediments improve the stable soil aggregates. Salinization can be
controlled by leaching the surface salts with rainwater irrigation. In alkali soils, application of
gypsum resulted in increased infiltration rate. The best method of avoiding waterlogging is by
providing surface drainage.
2. Managing soil nutrients
If yields are to be maintained and the soils used to produce crops on a continuing
basis, a method by which N, P, K and other nutrients can be replaced has to be adopted. If
yields are to be maintained and the soils used to produce crops on a continuing basis, a
method by which nitrogen, phosphorus, potassium and other nutrients can be replaced has to
be found. Nitrogen can be fixed by natural and symbiotic fixation like Rhizobia in legumes,
Azolla in rice and by using biofertilizers. Maintaining P, K and other nutrients normally
requires the use of inorganic fertilisers. Organic manures (FYM, compost, green manures,
farm wastes) should be used for balanced supply of essential nutrients as well as having
additional beneficial effects on the soil.
3. Managing soil physical conditions
Conservation tillage with lighter machinery is the most effective way to alter and
improve soil physical conditions. Under Indian conditions, satisfactory soil physical
condition of rainfed soils can be maintained by deep ploughing once in 3 to 5 years,

Water Harvesting
application of bulky organic manures in alternate years and shallow inter-cultivation for weed
management.
4. Improving soil moisture regime
There is no practical method by which available WHC of a soil can be increased.
Addition of silt, clay, organic matter etc. increases field capacity and also raises wilting point
leading to marginal increase in available WHC. If good soil is available, 1:1:1 ratio of soil,
organic matter and sand make an excellent mixture. If the soil is sand, a mixture of 1:1:1 with
soil, organic matter and clay soil is suitable. Never mix the heavy sticky clays in these soils.
Contour farming and sub-surface barriers helps to reduce runoff as well as soil loss.
5. Managing soil organic matter and soil biological conditions
Organic matter is a direct contributor to crop nutrition of crops and its role in
stabilising soil aggregates and supporting the soil organisms which create the pores through
which air and water move, has already been mentioned. In addition, it hinders the formation
of insoluble complexes of iron and aluminium with phosphate in acid soils thus avoiding
reduction in the amount of phosphate available to plants. Activities that promote the
accumulation and supply of organic matter, such as use of FYM, crop rotation, cover crops
and those that reduce decomposition rates, such as reduced and zero tillage, leads to an
increase in the organic matter content in the soil and its biological activities.
x-x-x-x-x

MANAGEMENT OF CROPS IN RAINFED AREAS
8 MANAGEMENT OF CROPS IN RAINFED AREAS
Under rainfed conditions soil moisture is the most limiting factor for crop production.
It is lost as evaporation from soil surface and as transpiration from the plant surfaces. The
combined loss of moisture through these two processes is known as evapotranspiration.
Crop management practices under rainfed areas:
1. Efficient cropping systems
Cropping intensity in dryland agriculture is, generally 100%, implying that single
crop is taken during the year. Cropping intensities of these areas can be increased through
intercropping and sequential cropping by way of more efficient use of resources. Crops and
cropping systems selected should match the length of crop growing season to avoid soil
moisture stress. Double cropping, either by sequential cropping or relay cropping, is possible
in regions with rainfall >900 mm, extended rainy season and high soil moisture storage
capacity. Double cropping is also possible with rainwater harvesting in farm ponds.
Intercropping of groundnut + castor (4:1) was pursued vigorously in Rajkot (Gujarat). Even
at Solapur, leafy vegetables and some short duration beans are grown as intercrops during the
rainy season.
Some dominant intercropping systems in different dry lands of India
Locations Soil
Rainfall
(mm)
intercropping Row ratio
Anantapur Alfisols 550 Groundnut + pigeonpea 7:1
Akola Vertisols 825 Sorghum + pigeonpea 2:1
Rajkot Vertisols 590 Groundnut + castor 4:1
Sholapur Vertisols 560 Chickpea + safflower 3:1
Bangalore Alfisols 890 Finger millet +
pigeonpea
8:1
Potential cropping systems (CS) for dryland agriculture
Annual rainfall
(mm)
Soil types Water
availability
(days)
Potential suggested CS
350 - 600 Alfisols
Aridisols
Vertisols
< 140
< 140
< 140
Single kharif crop.
Single crop either kharif or rabi.
Single rabi crop.
600 - 750 Alfisols
Vertisols
Entisols
140 - 210
Double cropping with sufficient
moisture conservation practices
or intercropping
750 - 900 Entisols
Vertisols
Alfisols
Inceptisols
> 210
Double cropping with moisture
conservation and monitoring
> 900 Vertisols
Inceptisols
> 210 Double cropping

2. Choice of crops and cultivars and crop substitution
Crops and varieties for drylands should have following characteristics:
 Plants with erect leaves and stem.
 Short duration and early vigour.
 Deep root system with ramified roots.
 Dwarf and moderate tillering in case of tillering crops and varieties.
 Resistance/tolerance to biotic stresses.
 Lesser period between flowering and maturity so that the grain filling is least
affected by adverse weather.
 Resistance/ tolerance to abiotic stresses.
 Low rate of transpiration.
 Less sensitive to photoperiod.
 Wider adaptability.
Traditional cultivars are of longer duration, photosensitive, inefficient users of soil
moisture and often have poor response to PoP. The guiding principle of choice of crops,
varieties and cropping systems for dry lands should be their suitability to vagaries of
monsoon. It is imperative to select crops and varieties, which possess wider adaptability,
shorter duration and evade or tolerate rainfall vagaries by virtue of their ability to maintain
high internal water content with deep root system and less transpiration. Such crops and
cultivars should be substituted with productive crops and cultivars.
Pulses and oilseed crops perform better than cereals if the sowings are delayed during
kharif. Among the pulse crops, cluster bean, moth bean and horse gram are better choice for
low rainfall areas relative to other kharif pulses. Among oilseed crops, castor and sunflower
perform better than groundnut under conditions of delayed sowing. For crops on receding soil
moisture during rabi, chickpea and lentil are preferred over peas and French bean. In the
rapeseed-mustard group of crops, taramira is the best choice for light soil with low moisture
storage capacity, followed by Indian mustard. Among the kharif cereals, coarse cereals
(millets and sorghum) are better choice over maize and rice, similarly, in rabi, barley does
well under conserved soil moisture than wheat. Among the millets, setaria (kodra) is most
suited for late sown condition without any serious effect on productivity.
3. Land preparation
Tillage is a well-known soil and water conservation practice which makes soil surface
more permeable to increase infiltration rate, which in turn reduces runoff, soil and nutrient
losses and enhance crop yields. Deep tillage in problem soils promotes better root system
development and helps in higher yields during low rainfall years, leading to more efficient
use of sub-soil resources. Off-season or pre-monsoon tillage also has a marked impact on
weed control and rainwater intake. All the cultural practices should be done across the slope
(contour cultivation) to reduce soil and water loss. By ploughing and sowing across the slope,
each ridge of plough furrow and each row of the crop act as obstruction to the runoff water.
4. Early sowing of crops in the season
It is an established fact that early sowing alone contributes to around 63% of the final
crop yield. Early sowing leads to optimum yield due to efficient use of growth resources
besides minimizing the incidence of pests and diseases. However, the problem is that how to
sow the crop early in the season when the onset of monsoon is delayed. The practical solution
to this problem appears to be land preparation for early/timely seeding, taking advantage of

summer showers. Taking advantage of these summer showers, the land can be prepared for
taking advantage of the early monsoon rains.
In some regions, where heavy clay soils dominate, sowing after rains is impossible
due to high stickiness of soil. As such, sowing may be done in dry soil, 2-3 weeks before the
onset of monsoon (dry seeding). For sorghum on black soils, dry seeding is recommended at
1-2 weeks before onset of monsoon with depth of sowing at 5 cm and seed hardening with
potassium di-hydrogen phosphate or potassium chloride. For cotton on black soils, dry
seeding is recommended at 2-4 weeks before commencement of monsoon, with a sowing
depth of 5 cm and seed hardening with CCC (500 ppm) or potassium chloride or 2% DAP.
5. Planting patterns and plant densities
Crop geometry refers to the arrangement of plant population (intra and inter-row
spacing) in the field. Choosing the optimum plant population and width of row spacing
continues to be one of the most difficult challenges for dryland farmers. At too densities, crop
yields are reduced because too much of soil water is used up to vegetative growth early in the
season; too low densities do not effectively exploit available moisture.
Recommendations are frequently made that do not differentiate between crop grown
on stored moisture (Sept.-Oct. to Jan.-Feb.) and those grown during rainy season (June-July
to Oct.-Nov.). For crops grown during rainy season, the usual recommendation is to increase
the distance between plants within the row, to adjust to a low moisture supply.
6. Managing soil crust problems
Soil crusts are dry, thin and hard soil surface layers that develop due to the action of
rain drop or irrigation water. On subsequent drying, it results in the development of
continuous layer of closely packed soil particles. Soil crusts often hinder the emergence of
seedlings and hence establishment of crop stand. Management practices to overcome crust
problems include:
 Shallow and dense sowing.
 Dragging heavy thorny branches on crusted soil surface.
 Loosening the crusted surface by using spike-tooth harrow.
 Mulching.
 Light blade harrowing 2-3 days after rain.
 Planting on shallow furrows and on sides of ridge
7. Minimizing Evaporation losses
There are three principles of evaporation control under field conditions.
a. Decreasing the turbulent transfer of water vapor to the atmosphere by growing plants,
raising wind breaks, straw mulches etc.,
b. Decreasing capillary conductivity by rapid drying of the surface soil layers.
c. Decreasing the capillary flow and moisture holding capacity of the surface soil layers.
For evaporation control, mostly mulches are used.
7.1 Mulches
Mulch is any covering material applied on the soil surface to reduce evaporation
losses. This material may be grown and maintained in place, or any material grown and
modified before placement or any material processed or manufactured and transported before
placement. or

Mulch is any material (crop residues, leaves, bark, manure, paper, plastic films,
petroleum products, gravel, coal etc.) used to cover the soil surface. Mulches are used for
various reasons but water conservation and erosion controls are undoubtedly the most
important for agriculture in dry lands.
7.1.2 Types of mulches
Based on the material used for mulching, mulches can be classified into following
categories:
a. Organic mulches: In this, crop residues of cereals and pulses, straw or stalks of cotton,
pigeonpea, rapeseed-mustard etc or stubbles of the crops such as maize, sorghum, sugarcane
including roots or husks of the seed of various crops or saw dust are left on the soil surface or
spread on the soil surface. Use of such materials as mulches help in soil and moisture
conservation, enhances nutrient availability; reduce soil crusting, soil salinity control, soil
structure improvement, crop quality control, weed control and moderate soil temperature.
b. Soil mulch: In soil mulching, a thin layer of loose soil surface that can be created by
frequently stirring the soil with surface tillage implements like danthis, guntakas (blade
harrows) etc. Surface mulch of dry soil of about 5 to 8 cm depth is created by stirring the
surface soil to turn it into fine dust particles. By adopting this practice, some amount of
moisture is lost from the upper layer. After the preliminary loss of moisture, the soil mulch
effectively controls further evaporation from sub-soil by breaking the capillaries continuity.
The soil mulch also prevents deep cracks in soils (especially black soils) by reducing the
direct action of atmosphere and hence evaporation is also reduced. The repeated inter-
cultivations done in rabi crops even in the absence of weeds help in reducing evaporation
losses. This system of mulching is highly suitable for moisture conservation in medium to
heavy texture soils, which tend to shrink and crack deeply on drying. Among the different
mulches soil mulch is the cheapest.
c. Dust mulching: The cracks are filled and covered by the loose layer of dust mulch. It is
used as a mid-season correction measure for moisture conservation.
d. Straw and stubble mulch: Straw and other crop residues like stubbles, groundnut shells,
cotton stalks etc; can be used as mulches on soil surface for moisture conservation. Straw
mulches reduce both the amount of energy absorbed by the soil and its movement above the
soil and hence reduce evaporation. However, the availability of adequate crop residues is a
problem for use as mulches.
e. Chemical mulches:
In chemical mulching, aluminum foils, plastic, polythene sheets etc. are spread on the soil
surface to moderate soil temperature for controlling weeds, to optimise temperature for
germination of seeds and to induce runoff of rainwater for ex-situ water conservation and
harvesting. Beside this, some chemicals such as hexadecanol (a long chain alcohol) when
mixed in the top 6 to 7 mm soil layer, results in a significant reduction of about 40%
evaporation. The surface layer of a treated soil dries out more rapidly than that of untreated
soil, creating a diffusional layer to evaporation.
f. Plastic mulches: Plastic mulches are very effective as mulches for evaporation control
provided cost is not a limiting factor. The plastic mulches may be either white or black. Black

plastic mulches will absorb the solar radiation and enhance the soil temperature for hastening
the germination of winter crops like wheat; barley etc., White plastic mulches will reflect the
incident radiation and reduce evaporation of soil moisture.
g. Vertical mulching: In heavy black soils, where infiltration of rainwater is a problem,
vertical mulching can be practiced keeping straw/ stalk/ stubbles as vertical mulch wherein
trenches of 40 cm wide, 15 cm deep are dug at 2 to 4 m interval across slope and filled with
stubbles or organic wastes to a height of 10 cm above soil surface. Around vertical mulching,
soils remained porous for longer period, thus maintains high rate of infiltration during the
rainy season. Vertical mulching has been found to enhance available soil moisture by 4 to 5
cm. Runoff is checked, collected in the shallow trenches and redistributed to adjoining soil
layers and infiltration is increased in black soils.
h. Live mulching: Is the term used to describe the covering of soil surface through the plant
canopy in intercropping system. Eg. Sorghum + forage cowpea, sorghum + sword bean
i. Pebble mulch: Where small pebbles like stone are placed on the soil surface. This
mulching will be successful in dryland fruit tree culture. The pebbles placed on the basins of
trees not only reduce evaporation but also facilitate infiltration of rain water into the basin.
Mulching is more advantageous during rabi/summer months than in kharif season.
Organic mulches particularly under receding soil moisture conditions increase crop growth
by conserving soil moisture.
7.1.3 Effect of mulches on soil properties
1. Soil structure: Surface mulches reduce the impact of falling raindrops, thus reducing
dispersion and sealing of soil pores leading to crust formation. Hence the soil structure
is protected. The mulches also improve soil structure due to decomposition of mulch.
2. Soil salinity: Under dry land conditions due to limited precipitation, soluble salts move
only to a limited depth and readily return to the surface as the soil water evaporates.
Due to salt accumulation in surface layers the germination and seedling establishment
may be adversely affected. Hence, mulches will reduce soil salinity problem by
increasing infiltration and reducing evaporation.
3. Soil water: The soil moisture content is improved by induced infiltration, reduced
evaporation and reduced transpiration by weeds. Surface mulches also obstruct the free
exchange of water vapor from soil surface into the atmosphere and hence increase soil
water content.
4. Soil temperature: The effects of mulches on soil temperature are highly variable and
depend up on the type of mulch material. White or reflective types of plastic mulches
generally decrease soil temperature, while black plastic mulches may increase soil
temperature. Crop residues moderate temperature by decreasing it in summer and by
increasing in winter season. This is due to combined effect of radiation interception and
evaporative cooling. The sugarcane trash mulch will enhance the germination of
sugarcane setts during summer by temperature reduction.
5. Soil erosion: The ease by which soil particles are moved by wind and water is related to
size of soil particles and wind and water velocity. The particles of size greater than 0.84
mm in diameter are generally not eroded by wind but they are easily eroded by water.

The mulches reduce the direct impact of falling raindrops on soil, thereby preventing
soil dispersion and consequent sealing of soil pores leading to reduced soil erosion.
Loss of soil moisture through evaporation from soil surface and through transpiration from
plant surfaces can be minimised by using mulches and antitranspirants.
8. Reducing losses due to transpiration
Nearly 99% of water absorbed by the plant is lost in transpiration. Hence transpiration
reduction is needed for maintaining favorable water balance in the plants. Transpiration has
become unavoidable evil as the stomata, which allow CO2 exchange also allows water vapour
transfer into the atmosphere.
There are four principles of transpiration control
a. By increasing leaf resistance to water vapor transfer by application of materials, which tend
to close or cover stomata (ex: both stomatal closing and film forming type of
antitranspirants).
b. By reducing amount of energy absorbed by leaf surface (Eg: leaf reflectants)
c. By reducing top growth of plants ( Eg: Growth retardants )
d. By increasing air resistance to water vapor transfer by shelter belts/ wind breaks
The transpiration losses can be controlled by use of Antitranspirants, use of Wind
Breaks/Shelter Belts and Efficient Weed Control.
8.1 Antitranspirants
Any material that is applied to transpiring plant surfaces with the aim of reducing or
inhibiting water loss from plant surface is called antitranspirants. The antitranspirants are also
known as transpiration suppressants. The best antitranspirants reduce transpiration losses up
to 30-40%. The possibility of reducing plant transpiration by chemical without reducing
photosynthesis is of great practical importance in arid and semi-arid regions. Where crop
production is limited by water scarcity, the maintenance of favourable water balances in
plants is must. However, the potential use of antitranspirants is not restricted to water
conservation.
8.1.1 There are four principles of transpiration control:
1. By increasing leaf resistance to water vapour transfer by application of materials
which tend to close or cover stomata. Both stomatal closing and film forming type of
antitranspirants are used for this purpose.
2. By reducing amount of energy absorbed by leaf surface (leaf reflectants).
3. By reducing top growth of plants (growth retardants).
4. By increasing air resistance to water vapour transfer by shelterbelts/ windbreaks
8.1.2 There are four types of antitranspirants.
a. Stomatal closing type: Transpiration mostly occurs through stomata on the leaf surface.
Some fungicides like PMA (phenyl mercuric acetate) and herbicides like atrazine in low
concentrations serve as antitranspirants by closing of stomata. PMA is known to inhibit
mesophyll photosynthesis. Though the success was reported from glasshouse studies, their
effectiveness under field conditions is limited.
b. Film forming type: The plastic and waxy materials, which form a thin film on the leaf
surface, retard the escape of water due to formation of physical barrier. The success of

these chemicals is limited since they also reduce photosynthesis. The desirable
characteristics of film forming type of antitranspirants are: they should form a thin layer,
they should be more resistant to the passage of water vapour than carbon dioxide and the
film should maintain continuity and should not break. These film forming antitranspirants
may be of either thin film or thick film.
Thin film forming type: Hexadeconol
Thick film forming type: Mobileaf, Polythene S-60
c. Leaf reflectant type: These are the white materials, which form a coating on the leaves
and increase leaf reflectance (albedo). By reflecting the radiation they reduce leaf
temperatures and vapour pressure gradient from leaf to atmosphere and hence reduces
transpiration. About 5% of kaolin spray reduces the leaf temperature by 3- 4°C and
decrease in transpiration by 22 to 28 per cent. Celite and hydrated lime are also used as
reflectant type of anti transpirants.
d. Growth retardant type: These chemicals reduce shoot growth and increase root growth
and thus enable the plants to reduce transpiring surface and resist drought conditions. They
increase root/shoot ratio. Eg : Cycocel – (2-chloroethyl) Trimethyl ammonium chloride
(CCC), Phosphon–D, Maleic Hydrazide (MH)
Antitranspirants generally reduce photosynthesis. Therefore, their use is limited to
save the crop from death under severe moisture stress. If crop survives, it can utilize the
rainfall that is received subsequently. Antitranspirants are also useful for reducing the
transplantation shock of nursery plants. They have some practical use in nurseries and
horticultural crops. Waxy materials are used for reducing post-harvest shrinkage of fruits.
Types of important antitranspirants
Stomatal closing type Film
forming
type
Reflectan
t type
Plant growth
regulators
(PGRs)
• Herbicides: 2,4-D, Phosphon-D,
Atrazine
• Fungicide: PMA
• Metabolic-inhibitors: Hydroxy
sulfonates, potassium metabisulphite
• Growth hormones: ABA, TIBA, CCC,
ethrel, succinic acid, ascorbic acid
• Mobileaf
• Hexadecon
ol
• Silicone
• Waxol
• Kaoline
• China clay
• CaCO3
• Celite
• Lime
water
• CCC
• Mepiquat
chloride
• Cvtokinins
• Salicylic acid
• Brassinolide
• Ascorbic acid
8.2 Use of wind breaks and shelterbelts:
Wind breaks are any structures that obstruct wind flow and reduce wind speed while
shelterbelts are rows of trees planted for protection of crops against desiccating wind, reduce
soil erosion and create a suitable micro-climate. Generally, shelterbelts give protection from
desiccating winds to the extent of 5-10 times their height on windward side and upto 30 times
on leeward side. A conical cross-section of windbreaks will provide the best protection from
the winds. A conical cross-section of windbreaks will provide the best protection from the
winds.

The direction from which wind is blowing is called windward side and direction to
which wind is blowing is called leeward side.
Shelterbelts are planted across
the direction of wind. They do
not obstruct the wind flow
completely. Depending upon
their porosity, certain amount of
wind passes through the
shelterbelts while the rest
deflects and crosses over the
shelterbelts. It thus reduces
wind speed without causing
turbulence.
The protection offered by the shelterbelts is dependent on the height of central tree
row in the shelterbelts.
Generally, shelterbelts give protection from desiccating winds to the extent of 5 to 10
times their height on windward side and up to 30 times on leeward side. Due to reduction in
wind speed, evaporation losses are reduced and more water is available for plants. The
beneficial effect of shelterbelts is seen more clearly in drought years. In addition, shelterbelts
reduce wind erosion.
8.3 Effective weed control:
Weeds transpire frequently greater amount of water per unit of dry matter production
than the crop plants. Therefore controlling weeds especially at early stages of crop growth
will be most effective means of increasing the amount of water available for crops. This is the
most useful method to reduce transpiration losses.
Weed management can be achieved through judicious management using good crop
agronomy and a variety of weed management strategies. Weed competition in crop field is
invariably severe in early stages of crop growth than at later stages. Generally, in a crop of
100 days duration, the first 35 DAS should be maintained weed free for optimum yield. In
general, crops must be maintained weed free during the first one-third period of life cycle.
The IWM combines different agronomic practices, mechanical, biological and herbicides use
to manage weeds, so that the reliance on any one weed control technique is reduced.
9. Nutrient management
Indian dryland are not only thirsty but also hungry. Studies on the extent of nutrient
deficiencies indicated that dryland soils are universally deficient in N, medium in P and high
in K content. The stained crop production on these soils requites regular nutrient inputs
through chemical fertilisers and organic manures to replenish soil nutrient reserves depleted
by crops. The quantum of nutrients available for recycling via crop residues and animal
manures is grossly inadequate to compensate for the amounts removed.
Following are the salient findings on fertiliser use in dryland agriculture:
1. Soils of dry regions are deficient in N in all soils, P in some soils, K is limited and Zn
and Fe are sporadically. Most economical responses were with low rates of 25-30 kg
N ha-1
. On heavy black soils, crops respond to about 30 kg P2O5 ha-1
. Legumes in
cropping system contribute up to 25 kg N ha-1
.

2. Response of post-rainy season crops to fertilisers will depend on stored moisture in
the profile and hence should be band placed in soil as basal application.
3. For kharif crops, N can be applied in splits depending on rainfall. Second split may be
avoided if the soil moisture is not adequate for top dressing in time. Legumes are
more responsive to P fertilisation.
4. Balanced fertiliser use resulted in yield advantage during normal rainfall year.
Thus, IPNS approach has come to play a key role in these areas. IPNS involves
judicious and combined use of fertilisers, bio-fertilisers, organic manures and growing of
legumes in the cropping systems. IPNS also encompasses balanced fertilisation and SSNM.
In case of Zn deficiency, 30 kg of zinc sulphate is applied once in three years.
10. Mid-season corrections
Aberrant weather like late onset of monsoon, dry spell immediately after sowing,
prolonged breaks during the crop period and early withdrawal of monsoon are common
features of rainfed agriculture. The success of the implementable recommendations, largely,
depends on the severity of soil moisture stress and stage of crop growth at which the crop is
subjected to soil moisture stress. To boost production some practices are adopted as per the
situation exists like-
Late onset of monsoon : Adopt dry seeding, transplantation and alternate
cropping systems
Dry spell immediately after
sowing
: Maintain optimum plant stand and crop substitution
Breaks during the crop
period
: Intercropping for risk distribution, reducing the crop
stand by thinning, rationing, mulching.
Early withdrawal of
monsoon
: Reduce plant population depending on the level of
stored soil moisture, surface mulching with organic
residues at 5 t/ha to minimise evaporation losses,
protective irrigation at moisture sensitive stages, if
possible, increasing frequency of inter-cultivation and
stripping of leaves and use of antitranspirants to control
moisture loss temporarily.
11. Alternate land use systems
Choice of land use systems viz., mono-cropping, double cropping, mixed cropping,
mixed farming, agri-horticulture and silvi-pastoral should be practiced depending upon the
rainfall, soil type and other climatic conditions.
12. Protective irrigation to crops from harvested rainwater is the best way to save crops.
x-x-x-x-x

CONTIGENT CROP PLANNING
9 CONTIGENT CROP PLANNING
FOR ABBERANT WEATHER CONDITIONS
Rainfall behavior in dry farming areas is erratic and uncertain. The deviations in
rainfall behavior include delayed onset, early withdrawal and intermediary dry spells during
rainy season. The adverse effect of these rainfall aberrations on crop growth vary with the
degree of deviation and the crop growth stage at which such deviations occur. Suitable
manipulations in crop management practices are needed to minimize such adverse effects of
abnormal rainfall behavior. These management decisions constitute contingency planning.
Such management practices done after crop establishment and in the middle of growth are
called midseason or midterm corrections.
Table 1 : Effect of Rainfall aberration on crop
Rainfall aberration Effect on crops
Delay in onset of rainfall Length of cropping season or cropping duration is reduced -
crop sowing is delayed
Early withdrawal or
cessation of rainfall
Moisture stress at maturity grain filling is affected (terminal
stress)
Intermediate dry spells
a. Immediately after sowing Germination will be affected, plant population will be reduced
b. At vegetative phase Affects stem elongation, leaf area expansion, branching or
tillering
c. At flowering Affects anthesis and pollination, grain / pod number is
reduced
d. At ripening Grain filling and grain size reduced
CONTINGENCY CROPPING
Contingency cropping is growing of a suitable crop in place of normally sown highly
profitable crop of the region due to aberrant weather conditions. In dryland agriculture,
contingency of growing another crop in place of normally grown crop arises due to delay in
the onset of monsoon. Depending upon the date of receipt of rainfall, crops are selected. It is
assumed that the rainfall for the subsequent period is normal and depending upon the
economic status of the farmer, certain amount of risk is taken to get good profits if season is
normal or better than normal.
Contingency cropping is highly location specific due to variation in amount and
distribution of rainfall. Especially in arid regions, the spatial distribution of rainfall is highly
variable. It is common to observe that rainfall received varies from field to field in the same
location. Temperature gradually falls from August onwards reaching minimum in November
and December. Contingency plan and midterm corrections vary with the type and time of
occurrence of rainfall aberration.
Crops have to be selected with suitable crop duration to coincide with the length of the
growing season. Generally short duration pulses like greengram, black gram and cowpea may
suit the situation. However if the monsoon turns to be extraordinarily good, opportunity is
lost if only short duration crops are sown. Farmers with economic strength and motivation for
high profits with some amount of risk can go for crops of long duration. The long duration

crops with flexibility or elasticity in yield are more suitable. For example, pearl millet, and
sorghum can be ratooned if monsoon extends. Sunflower can be introduced for higher profits
with certain amount of risk. Crops like sorghum, pearl millet, can be grown for grain if
monsoon extends and if not, fodder can be obtained.
Table 2 : Contingency Planning for Rainfall Abnormalities
Rainfall abnormality Contingency plan and midterm correction
1. Delayed onset of rainfall
a) Delay exceeding- 4 weeks Alternate crops of short duration to be sown
Delay in South west monsoon
Normal – June
Delay – July
Extreme Delay - August
Groundnut
Ragi/ Pearl millet
Sama (Little millet / Ragi)
Delay in North east monsoon
Normal – October
Delay – Early November
Extreme Delay - Late November
Cotton / Sorghum
Sunflower / Pearl millet / Ragi
Coriander /Bengal gram
b) Delay of 1 to 2 weeks Alternate varieties of short duration of the same crop
e.g. Sorghum Co 19 (150 days), Co 25 (110 days),
Red gram local (180 days), Co 5 (130 days)
2. Early withdrawal of rainfall Antitranspirants spray, harvesting for fodder (millets),
harvesting at physiological maturity
3. Intermediary dry spell
a. Immediately after sowing Gap filling with subsequent rains if stand reduction is
less than 20%. Re-sowing if stand reduction is more than
20%, mulching between crop rows. Stirring soil surface
to create dust mulch to reduce evaporation.
b. At vegetative phase Mulching, antitranspirants spray, spraying potassium
chloride, thinning of 33-50% population
c. At flowering Antitranspirants spray, harvesting for fodder and
ratooning with subsequent rains in millets (e.g. sorgum)
d. At ripening Antitranspirants spray, harvesting for fodder and
harvesting at physiological maturity
Crop planning for successful crop production under water scarcity and dry farming
condition:
In low rainfall and water scarcity situations during kharif, the crops like Bajra, Castor
and legumes crop like Tur, Moong, Black gram, Kidney bean, Guar and Cowpea. Crop
planning for successful crop production under water scarcity and dry farming condition
should be as under:
1. Bunding and leveling should be done to conserve the rain water in situ.
2. Sowing the crop at optimum time.
3. Tillage and sowing of the crop across the slope.
4. Use higher amount of organic manures like FYM, compost, vermicompost and cake.

5. Apply fertilizers at sowing under adequate soil moisture or as top dressing after
irrigation.
6. Use drip irrigation in wide spaced crops and sprinkler irrigation in narrow spaced
crops, if possible.
7. Inter culturing, weeding and crop protection measures should be done as and when
required.
8. Adopt mixed and inter cropping systems.
9. Raise crop in strip cropping.
10. Create farm pond for life saving irrigation.
Table3 : Suggested Contingency Crop Planning For Some of the Dryland Regions of
Gujarat
1. Latest Released varieties of major crops
The latest released varieties of major crops grown in Gujarat state are as under:
1 Paddy : Mahisagar, GAR 3, GR 14 and Gurjari
2 Maize : Gujarat Anand Yellow Maize Hybrid 1 and Gujarat Anand White
Maize Hybrid 2 – early maturity hybrids for rainfed tribal areas
3 Bajra : GHB 558, GHB 744, GHB 905 and GHB 732
4 Tur : AGT 2 and GT 104
5 Moong : Gujarat Anand Moong 5, GM 6 and GM 7
6 Guar : Gujarat Guar 1 and Gujarat Guar 2
7 Cotton (Desi) : Anand Desi Cotton 1 (ADC 1), GADC 2, Gujarat Cotton 13 & 21
are recommended for desi cotton growing area of Vagad and Bhal
regions
8 Cotton
(Irrigated)
: Gujarat Cotton Hybrid 6, Gujarat Cotton Hybrid 8, Gujarat Cotton
Hybrid 10, Gujarat Cotton Hybrid 12 and GTHH 49
9 Tobacco : MRGTH 1, GABTH 2 and Gujarat Anand Bidi Tobacco 11
(GABT 11)
10 Fodder sorghum : COFS 29, GAFS 11 and GAFS 12
11 Fodder Bajra : Gujarat Anand Forage Bajra 4
12 Castor : Gujarat Castor Hybrid 7, Gujarat Castor Hybrid 8, Gujarat Castor
Hybrid 9 and Gujarat Anand Castor 11
13 Sesame : Gujarat Till 3 & Gujarat Till 6, Purva
14 Soybean : NRC 37
15 Groundnut : GG 20, GJG 9, GJG 17 and GJG 22
16 Okra : GAO-5
3. Recommendation for late onset of monsoon
Generally, the period between 15th
June to 15th
September is considered as kharif season.
However, it is required to change the crop planning in kharif season, if the rainfall pattern is

found uneven. If there is a late onset of monsoon, then select the crops and their verities as
under:
1. Onset of monsoon in the first week of July- Groundnut varieties Gujarat Groundnut 2,
Gujarat Groundnut 5 and Gujarat Groundnut 7 as well as cowpea variety Gujarat
1should be grown.
2. If sufficient rainfall occurs during first fortnight of July - Crops like bajra, moong,
black gram, sesame, castor and tur should be grown.
3. If sufficient rainfall occurs at the end of July – Sesame (Purva 1) and forage sorghum
variety Gundari should be grown.
4. Recommendation for regular monsoon:
Table 4 : Selection of the crop and their varieties
1 Cotton : High yielding Bt cotton varieties as well as Gujarat Hybrid 8 and Gujarat
cotton 10,13,15,18 and 21. ADC 1 and 2 for rainfed cotton
2 Pearl millet : GHB 558, GHB 538, GHB 732, GHB 744 and GHB 905
3 Soybean : NRC 37
4 Groundnut : Spreading varieties
5 Castor : GCH 7, GCH 8, GCH 9 and Gujarat Anand Castor 11
6 Sesame : GT3, GT 4, GT 6 and Purva
7 Pigeon pea : AGT 2, GT 104 and Vaishali
8 Green gram : GAM5, GM 6, GM 7 and Meha
9 Mooth bean : Gujarat Mooth bean 1 and Baleshwar
10 Black gram : T 9 and Gujarat Black gram 1
11 Cowpea : Pusa falguni, Gujarat cowpea 1 and 2, AVCP 1
12 Sorghum
(Fodder)
: COFS 29, GAFS 11 and GAFS 12
13 Cluster bean : Gujarat Cluster bean 1 and Gujarat Cluster bean 2
5. Recommendations under long dry spell
There is a shortage of moisture in the soil, if the duration between two rainfall is
extended even under normal on set on monsoon. If this period between rainfall is
extended for longer time, than there is a partial or full failure of the crop. Under this
situation crop planning should be done as under
1. Do interculturing and weeding. Keep crop weed free and do mulching.
2. When moisture stress prevails, thinning should be done. If more moisture stress
prevails, remove alternate row and thin the plant in the field
3. Provide lifesaving irrigation to the crop if irrigation facility available
4. When sufficient rainfall received after dry spell, nitrogen fertilizer should be given as
top dress to the crops except groundnut.
5. When crop failed due to long dry spell, after receiving sufficient rainfall farmers can
grow hybrid pearl millet GHB 558, GHB 577.

6. Farmers should grow Sesame variety Purva 1 or Gujarat Til 1 or Castor variety
GAUCH 1 and GAC 11. In addition farmers can also grow fodder sorghum or rajaka
bajri.
7. Reduce the plants by harvesting the matured plants frequently, to save the conserved
6. Recommendations when heavy rainfall occurs at the end of monsoon during August
– September
Many times during end of September or beginning of October late rainfall received.
Under such situation following crop planning can be done.
1. For getting the benefits of good late rainfall sowing of fodder sorghum, short
duration semi rabi and rabi crops i.e. castor, mustard, gram, safflower, fodder
crops (maize/oat and lucerne) should be grown as relay crops between two rows
of long duration crops i.e. cotton, tur and fennel.
2. Gram, mustard and fodder sorghum can be grown after harvesting of early
maturing Kharif crops.
7. Recommendations made by Anand Agricultural University, Anand
1. The farmers willing to grow pigeon pea under organic farming system are
recommended to grow variety BDN 2 with vermicompost 1 t/ha or FYM 5 t/ha.
2. In pigeon pea cv. AGT 2 recommended for fertilizer dose and additional 20 kg S/ha
should be applied.
3. It is recommended that vegetable pigeon pea (GT 1) should be fertilized with 5 t
FYM/ha.
4. For getting higher yield of soybean cv. NRC37, it is recommended to sow the crop at
the onset of monsoon.
5. Farmers growing nematode resistant bidi tobacco variety ABT 10 are recommended
to topping the plant at 18 leaves and give 4-5 irrigations at 15-20 days intervals.
6. The farmers growing vegetable cowpea (Vegetable cowpea 1) are recommended to
fertilize with 5 t FYM/ha and 10:20:00 kg NPK/ha as basal dose. Sowing should be
done at 45 X 45 cm after seed treatment with Rhizobium and PSB culture (Both @ 5
ml/kg seed).
7. Drilled paddy varieties DDR 97 and Ashoka 200 F are recommended for rainfed
areas.
8. For rainfed areas, Gujarat Anand Yellow Maize Hybrid 1 as early variety and
Gujarat Anand White Maize Hybrid 2 is recommended for unirrigated kharif
cultivation.
9. For semi rabi castor cultivation, the sowing of GCH 7 variety should be done upto
10 to 25th
September at spacing of 120 cm x 75 cm.
10. Desi cotton early maturity variety Anand Desi Cotton 1 and 2 is recommended for
Vagad and Bhal regions.
11. It is not beneficial to apply phosphorus to desi cotton in North-Western Agro-
climatic Zone areas. It is recommended to apply 100 % nitrogen from FYM (8 t/ha)
or apply 75 % nitrogen from chemical fertilizer (30 kg/ha) + 25 % nitrogen from
vermicompost (600 kg/ha).

12. The farmers of Middle Gujarat Agro-climatic Zone growing semi-rabi green gram
are recommended to sow the crop during 3rd
week of September at 30 cm spacing for
obtaining higher yield and net return.
13. The farmers of Bhal and Coastal Agro-climatic Zone growing rainfed desi cotton are
recommended to sow cotton variety Gujarat Cotton 21 at 60 x 30 cm spacing to get
higher seed cotton yield.
14. The farmers of Middle Gujarat Agro-climatic Zone are advised to adopt semi rabi
pearl millet by transplanting one month old seedlings of GHB 744 or GHB 732
during 20th
to 30th
September for getting higher grain and dry fodder yield as well as
net return.
x-x-x-x-x

10 Watershed Management
Introduction
Soil, water and vegetation are the most vital natural resources for the survival of the
life on the biosphere. The prosperity and development of a nation depends, to a great extent
on natural resources and their management. Today these resources are under tremendous
stress due to ever increasing biotic pressure and mismanagement of resources. The optimal
management of these natural resources with minimal adverse environmental impact is a
desirable not only for sustainable development but also for human survival. For the efficient
management, one has to look for suitable units of management so that these resources are
handled and manages effectively, collectively and simultaneously. The soil, water and
vegetation can be managed efficiently by the unit system. The watershed is an ideal unit for
the natural resources management.
History of Watershed Development in India:
The earliest record of water management by manipulating the natural water regime in
India is found in Inamgaon near Pune. During the rule of the Mauryan Dynasty (320 BC) the
construction of water harvesting structure (WHS) and sustainable irrigated agriculture in
semi-arid regions attained a high level of perfection. The golden age of tank construction in
the Deccan Plateau was the reign of Chalukyas of Lakyan (973 to 1336 AD).
At national level, Soil Conservation Board was established in the Ministry of Food and
Agriculture during the first five year plan (1951-56). Under the control of this Board, a chain of
Soil Conservation Research, Demonstration and Training centres were established in the latter
period of first plan and early period of second plan.
Location Establishment Date Problem area covered
Dehra Dun
(HQ)
20th
September, 1954 North-western Himalayan Region
Ootacamund 20th
October, 1954 Southern hilly high rainfall region
Kota 19th
October, 1954 Ravine problem on the banks of Chambal river
Bellary 20th
October, 1954 Black soil region (semi-arid)
Vasad 11th
May, 1955 Ravine problem on the banks of Mahi river (Gujarat)
Agra 1st
October, 1957 Ravine problem on the banks of Yamuna river
Chandigarh 1st
October, 1957 Sub-mountain tracts in NE region of India (Shiwalik
hills)
Ibrahimpatnam 12th
October, 1962 Red soil region (semi-arid)
Watershed development (WSD) projects in the country has been sponsored and
implemented by GOI from early 1970s. Various WSD programmes were launched
subsequently in various hydro-ecological regions which were primarily focused on soil
conservation and water harvesting during 1980s and before. The GOI appointed a committee
in 1994 under the chairmanship of Prof. C.H. Hanumantha Rao. The committee gave new
guidelines for WSD programmes in 1995 and strongly emphasised on collective action and
participation of primary stakeholders, local community, NGOs and Panchayati Raj Institutions.

Need for unification of multiplicity of watershed development programmes within the
framework of a single national initiative was felt in 2001. A sub-committee constituted for this
purpose suggested common guidelines for watershed development projects through Nation
Authority for Development of Rainfed Areas (NAFDORA). This finally resulted in set up of
National Rainfed Area Authority (NRAA) in November, 2006. The Common guidelines for
WSD were released in 2008 (called Neeranchal guidelines) and revised in 2011 and 2013.
Chronology of watershed development (WSD) programmes and policies adopted in
India are given below:
1973-74 : Drought Prone Area Programme (DPAP)
1977-78 : Desert Development Programme (DDP)
1987 : National Research Centre for Agroforestry, Jhansi
1989-90 : Integrated Wasteland Development Programme (IWDP)
1989 : Integrated Afforestation and Eco-Development Scheme (IAEPS)
1990-91 : National Watershed Development Project for Rainfed Areas (NWDPRA)
1992 : Indo-German Watershed Development Programme (IGWDP)
1994 : Guidelines for Watershed Development
1998 : National Agricultural Technology Project (NATP)
1999-
2000
: Watershed Development Fund
2001 : Common Guidelines for Watershed Development (Revised)
2002 : National Afforestation Programme
2003 : Hariyali Guidelines released
2005 : Mahatma Gandhi National Rural Employment Guarantee Scheme
(MGNREGS)
2006 : Parthasarathy Committee report
2006 : National Rainfed Area Authority (NRAA)
2008 : Common Guidelines for WSD (called Neeranchal) released
2009 : Integrated Watershed Management Programme (IWMP)
2011 : Revised Common Guidelines for WSD were released
2013 : Revisions added to 2008 Neeranchal Guidelines
What is Watershed?
All land everywhere is part of some watershed. It is a land area that captures rainfall
and conveys the overland flow and runoff to an outlet in the main flow channel. The term
„watershed‟ strictly refers to the division separating one drainage basin from another. At
present, the term „watershed‟ is defined as „land area from which rainwater drains to a
common point‟. In this context, watershed is considered to be synonymous with „catchment‟
and „drainage basin‟. The word „watershed‟ introduced in 1920 was used for the „water
parting boundaries‟. Watershed or catchment or drainage basin is that land area which drains
to a common point called „outlet‟. With respect to the outlet, the watershed consists all of the
land area that collects water which flows to the outlet during a rainstorm. The watershed is
also known as ridgeline in U.K.

In physical terms, a watershed refers to the area lying above a given drainage point. It
may cover from <1 ha to thousands of hectares depending upon the point of reference.
Rainwater from a few hectares of land may drain into a common small stream. The few
hectares of land will, therefore, be the watershed area of that stream. This small stream runs
into a larger stream. The land area drained by the small stream makes up the watershed of the
larger stream into which they flow.
The watershed boundary is called the drainage divide. Precipitation received on the
opposite side of a drainage divide does not contribute to the runoff of the particular adjoining
watershed. Thus, watershed is a geo-hydrological unit of delineated area from which the
rainwater drains through a common outlet. The people, animals and vegetation are part of the
watershed community. All depends of the watershed and they, in turn, influence what
happens on the topography of that area-whether for good or bad.
Why Need of Watershed?
Since, watershed is a hydrological entity; natural resources management and their
utilization are best attempted by taking it as a unit of development planning. Proper rainwater
management, conservation, runoff control and development of water resources is essential for
meeting water demands of domestic, drinking, irrigation and industrial needs is possible
through it. Apart from development of agriculture, it may encourage areas of infrastructure
development, energy, health, education and prosperity among the community. Management
on watershed basis is now accepted as an essential feature for full and integrated development
of any area. Hence, a watershed approach is needed for overall sustainable development.
Hierarchy of a watershed
Watershed is a smaller geographical unit of a river system. It is also a self-contained
replica of the river system. The river system and its total catchment have a hierarchical
relationship with its smaller watershed units. Generally, rainwater on a ridge is divided in the
Where, Direction of water flow
A Minor ridgeline
B Major ridgeline
X Common outlet
Fig. A typical watershed
F
Far

direction of the slopes. The ridges acts as water divide, meaning that the rainwater diverges
from here in two or more directions following the slope of the land. Within the area
surrounded by the ridge (catchment area), the surface runoff of water converges to feed the
drainage system. The rainfall in the watershed turns into surface and groundwater flows and
passes through its drainage system, tending to exit the area through the lowest part of the
trunk stream.
The River Basin
Basin of a Tributary
Watershed or Sub-basin of a Stream
Watershed of a Stream of a Lower Order
Micro-Watershed of a Minor Stream
Fig. Watershed hierarchy and its river system
Small watersheds are drainage areas of a few thousands to a few tens of
thousands of hectares. Larger drainage areas are usually called river basin. The micro-
watersheds of agricultural fields may be considered as units which may range from a few
hectares to hundreds of hectares. In an agricultural watershed, there may be several fields of
farmers. The runoff collected from a watershed drains off into a natural water course. The
movement of runoff depends on the topography of the land. Soil conservation measures
adopted in a few fields in an isolated manner do not serve the purpose. Runoff, from fields
where erosion control measures are not adopted, enters the fields situated at lower end of the
watershed. It is necessary to adopt resource conservation measures over an entire watershed
instead of individual fields. In addition, development is taken in the entire watershed area
including wastelands, forests in addition to agricultural land from ridgeline to the outlet.
Delineation and Types of Watersheds:
The boundary of a watershed is defined by all points that shed water to the outlet. The
delineation of a watershed is important for hydrologic design. A Watershed Atlas of India has
been prepared by the Soil and Land Use Survey of India, 2018-19 which divides India into 6
major water resource regions, 37 river basins, 117 catchments, 588 sub-catchments and 3,854
watersheds, 49,618 sub-watersheds and 3,21,324 micro-watershed. There is both a macro
level and micro level delineation (the action of indicating the exact position of a border or
boundary).
Size of the watershed:
Questions are often asked on unit watershed size, particularly in the context of large-
scale watershed development. However, a particular size of a watershed is depends on the
objective of development. For major and medium irrigation projects, a watershed of
thousands of km² in size has to be considered. At small storage structure on a farm, the
watershed size may be only a few ha. However, the Government regards small catchments of
300–500 ha as a unit watershed. Large watersheds can be preferred in the plains valley areas

where pasture and forest development is the major objective. From the land management
point of view, a convenient size of watershed may vary from 500 –1000 ha. On an average,
the watershed size of 2,000 ha is considered reasonable for agricultural development. The
most appropriate size of the micro-watershed for development at field level is around 500
hectares.
The technique adopted by SLUSI for classification of watersheds is tabulated below:
S. N. Category of Hydrological Units Size Range
Macro delineation
1. Regions 270 – 1130 lakh ha
2. Basins 30 – 300 lakh ha
3. Catchments 10 – 50 lakh ha
4. Sub-catchments 2 – 10 lakh ha
5. Watersheds 0.2 – 1.5 lakh ha
Micro delineation
6. Macro-watersheds > 50,000 ha
7. Sub-watersheds 10,000 – 50,000 ha
8. Milli-watersheds 1,000 – 10,000 ha
9. Micro-watersheds 100 – 1000 ha
10. Mini-watersheds 1 – 100 ha
Problems of Watersheds:
Although, India has enormous potentiality to use water, the watershed areas of the
country are suffered from various problems like:
a) Physical problems: Steep slopes, badlands, weak geological formations. Siltation of
reservoirs, etc. can be found by observation of the existing maps. Problems such as heavy
and intense rainfall, excessive runoff and strong winds can be identified from the weather
and hydrological data.
b) Resource use problems: Problems such as shifting cultivation, excessive cropping, forest
destruction, fire, over grazing, human and animal pressure, poor road construction and
uncontrolled mining.
c) End problems: The final effects of watershed degradation i.e. soil erosion, landslides,
heavy sedimentation, water pollution, floods and droughts.
c) Socio-economic and other problems: Serious-socio-economic problems can be major
obstacles in carrying out watershed work. Any serious problem should be identified at the
beginning of the stage. These may include land tenure, poverty, lack of education, low
acceptance of innovations, seasonal shortage of labour etc.
Soil loss is a natural process and cannot be avoided completely but can be reduced to
a maximum acceptable rate. A mean soil loss of 11 t/ha is generally accepted as appropriate.
This value is as low as 2 t/ha where soils are shallow and highly erodible. It has been
estimated that in India, about 5334 MT of soil is eroded annually. Out of which 29% is

permanently lost to the sea, 10% is deposited in reservoirs and 61% is transported from place
to place.
What is Watershed Management?
Watershed management is the rational utilization of land, water and vegetation
resources for optimum production with minimum hazards. It involves management of land
surface and vegetation so as to conserve the soil and water for immediate use and long term
benefits for the farmers and the society as a whole. In a watershed management system
having favourable topography where improved land-use practices could be introduced easily
and precipitation distribution is not much uneven or erratic, such a system may be termed as
well-managed.
Watershed management is an integration of technologies within the natural
boundaries of the drainage area for optimum development of land, water and plant recourses
to meet the basic needs people in a sustained manner.
Watershed management may be defined as the process of formulating and
carrying out a course of action involving manipulation of natural, agricultural and
human resources of a watershed to provide resources that are desired by and
suitable to the watershed community, but under the condition that soil and water
resources are not adversely affected.
Concepts of Watershed Management:
It is not that watershed concept is not known, but many times the technical aspects of
the development either not well understood or are badly applied. Since, no „package of
practices‟ of wade-scale application of watershed technologies exists.
The intensification of land use in the traditional agricultural setting is self-defeating
because it is exploitive. The present agricultural practices greatly increase
runoff and soil erosion, reduce groundwater recharge, cause floods and
sedimentation of reservoirs etc. As a result, the cultivated land resource base is
shrinking and its productive capacity is diminishing.
The management of watershed resources to produce more than one product is called
“multiple use concepts”. Most of the development activities are closely associated with the
development and use of water resources. The main aim of multiple use management should
be to manage natural resources for the most beneficial combinations in present and future
uses. It is not necessary that every watershed is managed for all possible natural resource
products simultaneously. In the „watershed concept‟ development is not confined to
agricultural land alone but covers the entire watershed area.
Watershed management is a holistic development concept that encompasses land,
water, agriculture, forestry and all related enterprises matters in relation to the people who
inhabit the area and their socio-cultural system.
Watershed management envisages not only adoption of soil and water conservation
measures, but all other measures for increasing productivity, production and economic return
for the farmers in the watershed area. The object of watershed management is to meet the
problems of land and water use not in terms of any one measure, but on the basis that all
resources are interdependent and must be considered together.

As the entire process of agricultural development is depends on status of water
resources. Hence, it is essential to have various developmental programmes on watershed
basis in conjunction with basic soil and water conservation measures. The developmental
activities need to be taken up from ridgeline to outlet point (ridge to valley).
Watershed management programme in drylands aimed at optimizing the integrated
use of land, water and vegetation for providing an answer to alleviate drought, moderate
floods, prevent soil erosion, improve water availability and increase food, fodder, fuel and
fibre on sustained basis. The watershed is the natural framework for resource development in
relation to crop production.
Objectives of Watershed Management:
There are various descriptions of the objectives of watershed management, mostly
depending on the emphasis given in the proposed management programme. The main
objective of its development and management is proper use of all the available recourses of
watershed for optimum production with minimum hazards to natural resources. The overall
objectives of a watershed management either single or in combinations are outlined as:
1. To control damaging runoff and soil erosion.
2. To protect, conserve, and improve the natural resources for efficient and sustained
production.
3. To manage the watershed in order to minimize floods, droughts, landslides, etc.
4. To protect and enhance water resources, reducing silting of conservation structures
and conserving rainwater.
5. To increase the groundwater recharge through in-situ conservation and water
harvesting structures.
6. To rehabilitate the deteriorating lands.
7. To utilize the natural local resources for improving agriculture and allied occupations
so as to improve the socio-economic conditions of the beneficiaries.
The objectives of watershed management programme can also be described in
symbolic form of POWER. Here the letters symbolizes as:
P = Production of food-fodder-fuel-fruit-fibre-fish-milk on sustained basis
= Pollution control
= Prevention of floods
O = Over exploitation of resources minimization by controlling excessive biotic
pressure
= Operational practicability of all on farm operations and follow up programmes
W = Water storage at convenient locations for different purposes
= Wild animal and indigenous plant life conservation at selected places
E = Erosion control
= Ecosystem safety
= Economic stability
= Employment generation

R = Recharge of groundwater
= Reduction of drought hazards
= Reduction of siltation in multipurpose reservoirs
= Recreation
Principles of Watershed Management:
The important principles of watershed management techniques are:
1. Utilizing the land according to its land capability classification (LCC)
2. Putting adequate vegetative cover on the soil surface for controlling soil erosion,
mainly during the rainy season.
3. Conservation of maximum rainwater at the place where it falls on arable land by
conservation practices.
4. Draining out excess water with safe velocity to avoid soil erosion and storing it in
different rainwater harvesting structures for efficient future use.
5. Preventing gully formation and putting check dams and gully plugs at suitable
intervals to control soil erosion and increase groundwater recharge.
6. Safe utilization of marginal lands through alternate land use systems.
7. Maximizing productivity per unit area, per unit time and per unit water.
8. Improving sustainability of ecosystem and socio-economic status of the inhabitants.
The principles of modern watershed management programmes are holistic and
flexible, people-centred and participatory, multi-sectorial /multi-holders negotiations and
dialog process, integration of multi-disciplinary sectors and effective collaboration and
coordination.
The land is classified into 8 land capability classes, where class I to IV falls under
suitable for cultivation and V to VIII not suitable for cultivation but exclusively suitable for
other uses. The detailed „LCC for Watershed Management‟ is presented in the book
„Fundamentals of Watershed Management Technology‟ (Singh and Poonia, 2003).
Steps for watershed management action plan:
Watershed management involves determination of alternative land management
measures, for which it is essential that as much information as possible
is obtained about the problems of soil, land, vegetation, water, animals and inhabitants
involved in the watershed. In order to arrive at a practical solution to these problems, it is
necessary to go through ten distinct steps:
1. Identification and selection of watershed.
2. Description of watershed.
3. Analysis of problems and identification of available solutions.
4. Designing the technology components.
5. Preparation of base maps of watershed.
6. Cost-benefit analysis to indicate estimated cost.
7. Fixing the time frame.
8. Monitoring and evaluation to assess the progress of the project.

9. On-farm research to identify solutions for site-specific problems.
10. Good organizational structure.
FACTORS AFFECTING WATERSHED MANAGEMENT
The factors affecting watershed management are divided into five groups:
1. Watershed characteristics
2. Climatic characteristics
3. Land use patterns
4. Social status of inability
5. Organization
1. Watershed Characteristics
Watershed characteristics influencing watershed management include size, shape,
topography, slope, soils, vegetative cover and drainage density.
Size
Size of watershed determines the quantity of rainfall received, retained and surface
runoff. A small watershed is pronounced by overland flow which is the main contributor to
peak flow. The longer the watershed, the higher is the time of concentration while broader the
watershed the smaller is the time of concentration. A large watershed has no overland flow,
but channel flow is significant. Large watersheds are also affected by basin storage.
Shape
Shape contributes to the speed with which the runoff reaches the river. A long
catchment area will take longer to drain than a circular catchment. Basin shape is not usually
used directly in hydrologic design methods. A circular shaped watershed would results in
runoff from various parts of the watershed reaching the outlet at the same time. An elliptical
watershed having the outlet at one end of the major axis (having the same area as the circular
watershed) would cause the runoff to spread out over time, thus producing a smaller flood
peak than that of circular watershed.
Topography
Topographic configuration like slope, length, degree and uniformity of slope affect
both disposal of water and soil loss. Time of concentration and infiltration of water are a
function of degree and length of slope. Topography determines the speed with which the
runoff will reach a river. If the land slope increases four times, the velocity of water flowing
down the slope is doubled. When velocity is doubled, the erosive capacity increased four
times. Clearly, rain that falls on steep mountainous areas will reach the primary river in the
watershed faster than flat/slopping areas.
Slope
Watershed slope affects the momentum of runoff. Both watershed and channel slope
may be of interest. Watershed slope reflects the rate of change of elevation with respect to
distance along the principal flow path. It is usually calculated as the elevation difference
between the end points of the main flow path divided by the length. Elevation difference may
not necessarily be the maximum elevation difference within the watershed.

Soils
Soil of the watershed determines the amount of water that percolates, runoff and silt
which will be washed down the valley. Erodibility and transportation of a soil depends on
different soil characteristics.
Vegetative Cover
Vegetative cover is an important landscape element in any watershed. The type of
vegetation and its extent of vegetation on watershed lands affect the infiltration, water
retention, runoff production, erosion, sedimentation and the rate of evaporation. Vegetation
intercepts rainfall, impedes overland flow and promotes infiltration. All of these factors
reduce the quantity of runoff to streams. Vegetation binds and stabilizes soil, thereby
reducing the potential for erosion. Vegetation also stabilizes stream banks and provides
habitat for aquatic and terrestrial fauna. Vegetation functions to slow runoff and reduce soil
compaction, allowing better percolation of rain into soil and groundwater recharge. In
addition, the patterns, sizes and composition of the vegetation affect reduction of soil erosion.
Leaves and branches intercept the falling rain and reduce the effect of raindrop splash.
The lesser the falling height of the raindrops, the lesser will be its energy to cause splash
erosion. Vegetative litter builds up an organic surface that provides protection of the soil
layer. Root systems also help to keep soil material stable from moving down slope.
Drainage density
Drainage density is the total length of all the streams and rivers in a drainage basin
divided by the total area of the drainage basin. It is a measure of how well / poorly a
watershed is drained by stream channels. It is equal to the reciprocal of the constant of
channel maintenance and equal to the reciprocal of two times the length of overland flow.
Rivers that have a high drainage density will often have a more "flashy' hydrograph with a
steep falling limb. High drainage density indicates a greater flood risk.
2. Climatic Characteristics
The greatest factor controlling stream flow is the amount of precipitation that falls in
the watershed as rain or snow. However, not all precipitation that falls in a watershed flows
out and a stream will often continue to flow where there is no direct runoff from recent
precipitation.
Climate parameters like intensity and frequency of rainfall, temperature, humidity,
wind velocity and direction affects watershed functioning. It regulates factors like soil
properties and vegetation of the region. In the same way, the vegetation type of a region
depends totally on its climate type. It is estimated that the total energy of the raindrops equals
100 HP on one ha land during the one cm rainfall for one hour. Thus, all climatic factors
determine the amount of surface runoff and transportability of soil particles.
3. Land Use Pattern
Watersheds maintain the health of forests, fisheries, wetlands, coastal resources,
agricultural landscapes, habitat and local communities. Protecting watersheds ensures
sustainable environment that supports recreational activities and a healthy economy.
Type of land use, its extent and management are the key factors which affect
watershed behaviour. Judicious land use by users is of vital importance to watershed
management and functioning. Change of land use within the watershed, especially within the

variable source area, greatly affects the collection capacity and consequent runoff behaviour
of the watershed. If the land use changes are local, then the impact of such changes is
especially apparent in the storm hydrograph.
4. Social Status of Inability
Common contributors to water pollution are nutrients and sediment which typically
enter stream systems after rainfall washes them off poorly managed fields. These types of
pollutants are considered nonpoint sources of pollution because the exact point where the
pollutants originated cannot be identified. Such pollutants remain a major issue for water
ways because of the difficulty to control their sources hinders any attempt to limit the
pollution. Point source pollution originates a specific point of contamination such as if a
manure containment structure fails and its contents enter the drainage system.
5. Organization
The success of any WSD programme is depends on the type of organization. This is
the crucial factor for watershed development. Land use questions can only be tackled in close
collaboration with the owners and the local participatory inhabitants. To augment such
interaction, the size of the watershed should not be too large or too small. People‟s
participation is only effective when a watershed have an organized development agency.
COMPONENTS OF WATERSHED MANAGEMENT PROGRAMME
The main components of watershed management programmes include:
1. Soil and water conservation
2. Water harvesting
3. Crop management and
4. Alternate land use systems
1. Soil and water conservation measures:
Soil conservation is using and managing the land based on the capability of the land
itself involving the application of the best management practices leading to profitable crop
production without land degradation. The basic principle behind soil conservation measures
is to minimize the velocity of surface runoff by transforming undulating topography into
relatively flat surfaces which increases the opportunity time of the rainwater to infiltrate into
the soil for future use by the crops.
Based on the nature and type of hydraulic barriers and their cost, the conservation
measures in arable lands can be divided into three categories:
A. Permanent treatments (Hardware treatments):
Bunds, terraces and waterways are the permanent measures in watershed management
project. These measures are provided to improve relief, physiography and drainage features
of watershed, aimed at controlling soil erosion, regulating surface runoff and reducing peak
flow rates. Contour bunds are suitable for low rainfall areas (<600 mm) and in permeable
soils having slope up to 6%. Graded bunds are suitable for high rainfall areas (>600 mm) and
for poor permeable soils having 2-6% slope. Bench terracing is suitable for soils having
slopes 16-33%. Bench terraces reduce both slope length and degree of slope. At Ootacamund
erosion rate decreased from 39 t/ha to less than 1.0 t/ha on 25% sloping land by bench
terracing.

B. Semi-permanent treatments (medium software treatments):
These are usually inter-bund treatments where field sizes are large in conventionally
bunded area. They are adopted to minimize the velocity of overland flow. It includes key-line
bunds, strip levelling, live beds and vegetative. These measures may last for 2 to 5 years. In
vegetative barriers, one or two barriers of close growing grasses or legumes along the bund
and at mid length of slope can filter the runoff water or slow down over land flow. Khus grass
(Chrysopogon zizanioides) is widely recommended as vegetative barrier.
C. Temporary treatments (short software treatments):
These are simple treatments for in- situ moisture conservation and needs renovation
every year. Simple practices like contour farming, compartmental bunding, BBF, dead
furrows, tillage and mulching have gained wide acceptance in the recent past.
Ridges and furrows: The field must be formed into ridges and furrows. Furrows of 30-45
cm width and 15-20 cm depth are formed across the slope. The furrows guide runoff water
safely when rainfall intensity is high and avoid water stagnation. They collect and store water
when rainfall intensity is less. It is suitable for medium deep to deep black soils and deep red
soils. It can be practiced in wide row spaced crops like cotton, maize, chillies, tomato etc. It is
not suitable for shallow red, shallow black and sandy soils.
Tied ridging: It is a modification of the ridge and furrow system, wherein; the ridges are
connected or tied by a small bund at 2-3 m interval along the furrows to allow the rainwater
collection in the furrows; which slowly percolated into the soil.
Dead furrows: At the time of sowing or immediately after sowing, deep furrows of 20 cm
depth are formed at intervals of 6 to 8 rows of crops. No crop is raised in the furrow. The
dead furrows can also be formed between two rows of the crop, before the start of heavy
rains. The dead furrows increase the infiltration opportunity time.
Compartmental bunding: Small bunds of 15 cm width and 15 cm height are formed in both
directions to divide the field into small basins or compartments of square or rectangular shape
of 6×6 m to 10×10 m size using bund former. They are useful for temporary impounding of
rain water which facilitates high infiltration resulting in high moisture storage in the soil. It is
recommended for black soils with a slope of 0.5 to 1 per cent. Maize, sunflower, sorghum
performs well in this type of bunding.
Scooping: Scooping the soil surface to form small depressions or basins help in retaining rain
water on the surface for longer periods. They also reduce erosion by trapping eroding
sediment and this practice can reduced runoff by 50% and soil loss by 3 to 8 t/ha.
Inter row/plot water harvesting: Water is drawn from part of a small catchment and used in
lower portion for crop production.
Zing/ bench terracing: These are developed by A.W. Zing in USA. Zing terracing is
practiced in low to medium rainfall areas in black soils with contour bunds. It is a method of
land shaping where lower one third portion of the land adjacent to the contour is levelled to
spread to the runoff water coming from the remaining two-third portion of the field. This
rainfall multiplication technique ensures at least one good crop in one-third area even in low
rainfall years. Usually during medium rainfall years water intensive crops (like paddy) are
cultivated in the levelled portion (receiving area) while dry crops are cultivated in the
unlevelled (donor) area.

2. Water harvesting in rainfed agricultural areas:
Runoff farming and rainwater harvesting agriculture are synonymous terms, which
imply that farming is done in dry areas by means of runoff from a catchment. It is a process
of collection of runoff water from treated or untreated land surfaces/catchments or roof tops
and storing it in an open farm pond or closed water tanks/reservoirs or in the soil itself (in situ
moisture storage) for irrigation or drinking purposes. Runoff farming is basically a water
harvesting system specially designed to provide supplemental irrigation to crops, especially
during periods of soil moisture stress. The rainwater harvested from catchment is used in
command area.
3. Crop management in rainfed agricultural areas:
Location-specific package of practices for dryland crops have been developed by dryland
research centres and SAUs for all the crops. The important crop management practices are:
a. Choice of crops b. Land preparation c. Contour cultivation
d. Strip cropping e. Mulching f. Cover crops
g. Effective weed control h. Organic manures/ residues i. IPNM
j. Cropping systems k. Use of antitranspirants l. Windbreaks/ shelterbelts
a. Choice of crops: Tall growing row crops (sorghum, maize, bajra etc.) are not effective in
conserving soil as they expose majority of the soil, hence known as erosion-permitting crops.
Whereas close growing crops (cowpea, peanut, greengram, blackgram etc.) protect the soil
are known as erosion-resisting crops as they are very effective in reducing soil loss by
minimising the impact of raindrop and acting as obstruction to runoff.
b. Land preparation: Tillage is a well-known soil and water conservation practice which
makes soil surface more permeable to increase infiltration of water into the soil, which in turn
reduces runoff, soil and nutrient losses and enhance crop yields. Tillage makes the soil
surface permeable and thus, support water intake. Deep tillage (25-30 cm) assists in opening
up of hard soil layers and faster penetration of rainwater. Deep tillage in problem soils
promotes better root system development and helps in higher yields during low rainfall years.
Off-season tillage has a marked impact on weed control and rainwater intake. Conservation
tillage, which ensures at least 30% coverage of the soil surface with crop residue play very
important role in organic carbon build up and soil and moisture conservation. Conservation
tillage includes stubble mulch tillage, minimum tillage and zero tillage. Low intensity tillage
favours consolidation of soils and imparts erosion resistance.
c. Contour cultivation: A line joining the points of equal elevation is called contour. All
cultural practices such as ploughing, sowing, inter-cultivation etc. are done across the slope to
reduce soil and water loss.
d. Strip cropping: It is a system of growing of few rows of erosion-resisting crops (ERC)
and erosion-permitting crops (EPC) in alternate strips on contour (across the slope) with the
objective of breaking long slopes to prevent soil loss and runoff. Close growing ERC reduce
the transporting and eroding power of water (erosivity) by obstructing runoff and filtering
sediment from runoff to retain in the field. The normal ratio of ERC and EPC is 1: 3. The

strip cropping is simple, cheap and effective soil conservation practice and can be adopted by
the farmers.
It is divided into four types:
Contour strip cropping: When EP & ER crops are grown in alternate strips along the
contours.
Field strip cropping: Alternate strips of EP and ER crops are raised across the general slope
not necessarily on exact contour.
Wind strip cropping: When EP and ER crops are grown across the direction of the most
prevailing wind irrespective of the contour.
Buffer strip cropping: This type of strip cropping is practiced in areas having steep slopes and
badly eroded soils. Here strips of permanent cover crops (perennial
legumes, grasses, shrubs) are alternated with field crops.
Strip widths of EP and ER crops at various slopes
Slope % Width of EP strip
(m)
Width of ER strip
(m)
Up to 1 45 9
1 - 2 24 6
2 - 3 13.5 4.5
e. Mulching: Mulching of soil with available plant residues reduce soil loss considerably by
protecting the soil from direct impact of raindrop and reducing the sediment carried with
runoff. A minimum plant residue cover of 30% is necessary to keep runoff and soil loss
within the acceptable limits. Vertical mulching reduces soil loss particularly in Vertisols by
increasing infiltration. The types of mulching are dust mulch, straw/stubble mulch, plastic
mulch, chemical mulch, live mulch, pebble mulch, etc.
f. Cover crops: Good ground cover by canopy gives the protection to the land like an
umbrella and minimizes soil erosion. Besides conserving soil and moisture, the cover crops
hold those soluble nutrients, which are lost by leaching, adds organic matter and control
weeds. The legumes provide better cover and better protection. Among the legumes cowpea
has been found to produce maximum canopy followed by horsegram, greengram. blackgram
and dhaincha.
g. Effective weed control: In rainfed areas, limited generation of weeds occurs due to
shorter period of water availability. However, their control is must. Weeds are removed in
very early stage (before flowering) by repeated blade harrowing. Intercultivation is very
common practice of weed control in rainfed areas.
h. Organic manures and residues: Organic manures, besides supplying nutrients improve
soil physical conditions by way of soil aggregation. Improvement in soil aggregation
improves water intake rate of soil leading to reduced runoff.
i. Integrated plant nutrient management (IPNM): Inadequate supply of plant nutrients and
continuous use of inorganic fertilisers resulted in soil degradation. Sol health restoration
should be the major in sustaining crop productivity in rainfed agriculture. Use of manures and

bio-fertilisers along with limited use of inorganic fertiliser appears ideal for restoring the
degraded soils for sustained productivity of rainfed soils.
j. Cropping systems: Mono-cropping of EP crops accelerate soil and water loss year after
year. Intercepting EP and ER crops or their rotation has been found effective for soil and
water conservation. As the pulse crops are effective for soil conservation due to their
smothering effect, they should be sown in time to develop adequate canopy by the time of
peak rate of runoff. Intercropping is recommended in areas receiving rainfall in the range of
600-850mm/annum. Double cropping is highly suitable to areas receiving rainfall >900 mm
and moisture storage capacity of 200 mm/m depth.
4. Alternate land use systems (ALUS)
To cope up with increasing population of both human and livestock and rising
demand for food, fodder and fibre, more and more marginal and sub-marginal lands are
brought under cultivation. These lands are unable to sustain productivity. Cultivating such
lands leads to imbalances in the ecosystem. Hence, a pattern of land use that is different from
the conventional can be described as an alternative land use system. When land is put under
alternative production system to match its capability more appropriately to the new land use
and achieve more sustainable biological and economic productivity on long term, it is known
as alternative land use.
Advantages of alternative land use systems
1. Optimising resource use by enhancing biological productivity and profitability,
2. Conserving and enhancing the quality of resource base,
3. Integrating crops (arable and pastoral) and livestock,
4. Making agriculture less dependent on off-farm inputs,
5. Generating employment potential, and
6. Improving overall quality of farm life.
Depending upon component of farming systems, various types of land use can be
integrated on watershed system mode. Alternate land use systems are applicable to all classes
of land aiming at generation of assured income with minimum risk through efficient
utilisation of available resources. Commonly known alternate land use systems are
agroforestry, tree farming and ley farming.
5. Agroforestry:
Agroforestry is a collective name for a land use system in which woody perennials
(trees/ shrubs) are deliberately mixed on the same land management unit as crop and/or
animals either in some forms of spatial arrangement or in time sequence. Agroforestry based
ALUSs reduces runoff erosivity and soil erodibility through dissipation of rainfall energy by
canopy at low height, surface litter, obstructing overland flow, root binding and improving
soil health. Satisfactory crop yield can be obtained when compatible species are grown and
soil-water resources are sufficient to meet the water needs of both the species. Trees, crops
and animals are the three basic sets of elements of components of an agroforestry. These are
classified as:
1. Agri-silvicultural : Crops and trees including shrubs/vines/trees
2. Silvi-pastoral : Pastures, animals and trees

3. Agri-silvi-pastoral : Crops/pasture animals and trees
4. Agri-horticulture : Crops (short duration) and fruit species
5. Silvi-horticulture : Trees and fruit species
6. Silvi-horti pastoral : Trees/fruit species, animal and pastures
However, prolific seeding habit of component trees like subabul resulting in more
weed growth and reduced crop yields; root and shade effects of trees on cultivated crops upto
20 m in case of Acacia nilotica; harbouring birds, pests and diseases; reduced scope of
mechanisation, more labour intensive and allelopathic effects of trees on cultivated crops are
the major disadvantages of the agroforestry based land management system.
6. Alley Cropping:
Alley cropping is broadly defined as the planting of rows of trees/ shrubs (single or
multiple) at wide spacing, creating alleyways within which agricultural crops are produced.
The shrub/tree rows are called hedgerows and the space between where the crops are grown
are called alleys. Alley cropping is an agroforestry practice intended to place trees within
agricultural cropland systems. The purpose is to enhance/ add income diversity (both long
and short range), reduce wind and water erosion, improve crop production, improve
utilisation of nutrients, improve wildlife habitat or aesthetics, and convert cropland to forest.
Based on the objectives, three types of alley cropping systems are recognised:
1. Forage-alley cropping
In this system, both yield of crop and forage assume importance. The tree species
suitable for hedge rows are Leucaena leucocephala, Colliendra and Sesbania. Pigeonpea or
castor crops are suitable for growing in the alleys of Leucaena.
2. Forage-cum-mulch system
In this system, hedgerows are used for both forage and mulch. Loppings are used for
mulching during the crop season and used as fodder during off season. Substantial increase in
crop yields of sorghum, groundnut, greengram and blackgram have been observed at several
places.
3. Forage-cum-pole system
Leucaena alleys are established at 5 m intervals along the contours. Hedgerows are
established by direct seeding and topped every two months at 1 m height during crop season
and every 4 months during the off-season. A Leucaena plant for every 2 m along hedgerows
is allowed to grow into a pole.
7. Tree farming:
Trees can flourish and yield abundantly where arable crops are not profitable. Farmers
of dry lands are inclined to tree farming because of labour cost, scarcity at peak periods of
farm operations and frequent crop failure due to drought. Multipurpose tree species (MPTS)
are those trees, which are purposely grown to provide more than one significant product or
service function in the land use system in which they grow. On small farms, this, generally,
means both wood and foliage use from the same tree. Their ability to provide fuel and timber,
nitrogen, fodder, food, resins, fibre, medicines, shade etc. make them MPTS. For Gujarat
plains and hills, Prosopis cineraria is the best MPTS followed by Eucalyptus hybrid,
Ailanthus excelsa, Dalbergia sissoo and Leucaena.

8. Ley farming:
This system involves rotation of legume forages with cereals. A rotation system
which includes pasture (ley) for grazing and conservation is called alternate husbandry or
mixed farming. It is a low risk system for dry lands. Inclusion of Stylosanthes hamata
(legume fodder) in rotation improved soil fertility besides increasing crop yields.
Recommended ALUS Options for Different Agroclimatic Conditions
Annual
rainfall
Soil type/
depth
Land use
systems
Suitable tree/grass/legume species
< 500 Shallow
(0-0.30 m)
Tree farming Prosopis cineraria, P. juliflora, Acacia aneura, A.
nilotica,
A. tortilis, Pithecelliobium duice
Medium
(0-0.45 m)
Pasture
management
Lasiurus sindicus (light textured soils), Cenchrus
setigerus,
Sehima nervosum, Stylosanthes scabra, Clitoria
ternatea
500 - 750
mm
Shallow
(0-0.30 m)
Silvi-pastoral
system
Acacia nilotica, Colophosphermum mopane,
Dalbergia
sissoo, Hardwickia binata, Cassia sturti, Albizia
amara,
Leucaena leucocephala, Cenchrus ciliaris, C.
setigerus,
Dicanthium annulatum, Panicum antidotale,
Stylosanthes
hamata, Macroptillum atropurpureum.
Medium
(0-0.45 m)
Horti-pastoral
system
Annona squamosa, Zizyphus mauritiana, Syzigium
cuminil, Emblica officinalis, Tamarindus indica,
Feronia
limonia, Aegle marmelos, Cenchrus ciliaris, Panicum
antidotale, Urchloa mosambicensis, Stylosanthes
hamata,
Macroptilum atropurpureum, Clitoria tenatea.
> 750
mm
Shallow
(0-0.30 m)
Ley farming /
Silvi-pastoral
system
3 years Stylosanthes hamata and 4th
year arable crop
(sorghum on heavier soils, pearl millet on lighter soils)
Silvi-pastoral system as above.
Medium
(0.30-0.45
m)
Ley farming /
Horti-pastoral
system
Ley farming as above.
Mangifera indica, Achras zapota, Psidium guajava,
Emblica
officinalis, Stylosanthes hamata/ Macroptilium
atropurpureum
Deep
(>0.45 m)
Agri-silvi or
Agri-horti
system
Acacia ferruginea, Prosopis cinneraria, Tectona
grandis,
Hardwickia binata, Dalbergia sissoo + arable crops.
Mangifera indica, Achras zapota, Psidium guajava +
arable crops.

Integrated Watershed Management:
In dry farming areas, watershed approach provides an ideal means for
integrated development. This approach will further the cause of sustainability which
requires the best land and water use and ecological sustenance. There is need for
a multi-pronged approach to maximize crop production and also
ensuring stability in rural incomes. The various steps used in this are in situ moisture
conservation, water harvesting and crop production; conjunctive use of rainwater; crop
substitution with site-specific crop production techniques; afforestation and dryland
horticulture, discouraging faulty practices, encouraging dairying, sericulture, cottage
industries; custom-hire services for employment generation and training of inhabitants to
develop a participatory model watershed.
Issues before Watershed Management Programmes: The major issues are-
1. Stakeholders were neither involved in selection of project ingredients nor encouraged
others to participate in various project activities.
2. Benefits of watershed management accrued mainly to farming community where as
the livelihood securities of the landless families have not been taken care.
3. The portfolio of alternate livelihood opportunities created for the beneficiaries could
not cope with stress and shock and the primary stakeholders could not maintain
activities after the completion of project period.
4. In majority of the cases sustainability had been causality mainly due to absence of
primary stakeholders in project planning and implementation stages.
Planting and maintaining trees were considered noble acts. They were considered better
than having sons, as has been said in Agnipuran (1000 BC)
दशक्र
ु प समावापी दशवापी समाहदः ।
दशहद समपुत्रौ दशपुत्र समातरः ।।
Ten wells are equal to one tank, ten tanks are equal to one lake, ten lakes are
equal to one son and ten sons are equal to one tree for giving Punya. In the Purans it is
said
अपुत्रस्य पुत्रत्वं पाद्य़ा इह क
ु ववते ।,
Which means for those who do not have sons; trees are like sons for them.
x-x-x-x-x

Glossary
Rainfed Agriculture and Watershed Management: Mevada K. D., Poonia T. C, Saras Piyush and Deshmukh S.P. Page i
Glossary of Selected Terms
Accelerated erosion: Erosion much more rapid than normal, natural geological
erosion, primarily as a result of the influence of the activities of man or, in some
cases, of animals.
Afforestation: Conversion of bare land into forest land by planting of forest trees. The
planting of a forest crop on land that has not previously, or not recently, carried a forest crop.
Agroforestry system: A land-use system in which woody perennials (trees, shrubs, palms,
bamboos) are deliberately used on the same land management unit as agricultural crops
(woody or not), animals or both, either in some form of spatial arrangement or temporal
sequence. In agroforestry systems there are both ecological and economic interactions
between the different components.
Agroforestry: Any type of multiple cropping land-use that entails complementary relations
between trees and agricultural crops.
Agrostology: The study of grasses.
Alley cropping: An agroforestry intercropping system in which species of shrubs or trees are
planted at spacings relatively close within row and wide between row, to leave room for
herbaceous cropping between, that is, in the 'alleys' (syn: hedgerow intercropping).
Aquifer: A saturated, permeable layer of sediment or rock that can transmit significant
quantities of water under normal pressure conditions.
Arable land: Land that is capable of being cultivated and supporting agricultural production.
Arboriculture: A general term for the cultivation of trees.
Badland: A land type generally devoid of vegetation and broken by an intricate
maze of narrow ravines, sharp crests, and pinnacles resulting from serious erosion
of soft geologic materials. Most common in arid or semi-arid regions. A miscellaneous land
type. Term used to describe a semi-arid landscape that has been influenced by heavy fluvial
erosion. Characterized by deep ravines and gullies, shape ridges, and a generally barren
surface.
Base flow: Stream discharge derived from effluent ground-water seepage.
Bed load: Portion of the stream load that is carried along the stream bed without being
permanently suspend in the flowing water.
Bedrock: The solid rock underlying soils and the regolith in depths ranging from
zero to several hundred metres.
Bench mark: A point of reference in elevation surveys.
Bench terrace: A shelf-like embankment of earth with a level top and steep or
vertical down hill face, constructed along the contour of sloping land to control runoff
and erosion.
Blowout: An excavation in areas of loose soil, usually sand produced by wind
erosion.
Broad-base terrace: A ridge type terrace 25 to 50 cm high, and 4.5 to 9.0 m wide
with gently sloping sides, a rounded crown, and a dish shaped channel along the
upper side constructed to control erosion by diverting runoff along the contour at a
non-scouring velocity. It may be level or have a grade toward one or both ends.
Buffer strips: Contour strips of grass or other erosion resisting vegetation between
or below cultivated strips or fields.

Glossary
Rainfed Agriculture and Watershed Management: Mevada K. D., Poonia T. C, Saras Piyush and Deshmukh S.P. Page ii
Buffer zone: An area around a forest, national park, or any other conserved place that
provides the local community with products that they would otherwise take from the forest,
or that provides an opportunity to produce alternative products.
Bund: A barrier on the surface of the soil on sloping land to prevent runoff and soil erosion.
Carrying capacity: Amount of animal life, human life or industry that can be supported
indefinitely with available resources on a given area. In wildlife management, the optimum
population density that a given environment or range is capable of sustaining permanently.
Catchment area: The land surface on which rain falls. Sometimes called a 'water catchment'.
When referring to particular streams or rivers, it is the land surface from which water (rain)
flows into them, sometimes through tributaries (feeder streams).
Cavitation: Process of intense erosion due to the surface collapse of air bubbles found in
constricted rapid flows of water. Causes the detachment of material from a surface.
Check dam: A small, low dam constructed in a gully or other water course to
decrease the velocity of stream flow, for minimizing channel scour and promoting the
deposition of eroded material. Usually built of inexpensive and temporary materials
where dependence for ultimate protection in placed on vegetative cover.
Chiselling: The breaking or shattering of compacted soil or subsoil layers by use of a chisel.
Clear cutting: Strictly, the removal of an entire standing crop of trees. In practice, may refer
to exploitation that leaves much unsaleable material standing. Also termed 'clear felling'. An
area from which the entire timber stand has been cut. Removal of the entire stand in one cut.
Reproduction is then obtained with or without planting or artificial seeding.
Companion crop: A crop which is grown with another crop.
Concentrated flow: The flowing of a rather large accumulated body of water over,
or one which corresponds to a net rain storm of duration longer than one unit period.
Concentration point: The single geographical location at which all surface drainage
from a given area comes together as outflow.
Concentration time: The time required for discharge from the most distant point in a
drainage area to reach the concentration point.
Conservation tillage: An agricultural system using tillage techniques designed to reduce soil
erosion and overland flow. Most conservation tillage techniques involve less manipulation of
the soil than conventional techniques, leaving more plant matter on the soil surface.
Contour farming: Conducting field operations, such as ploughing, planting,
cultivating and harvesting on the contour or a right angles to the natural direction of
slope.
Contour furrows: Furrows ploughed on the contour on pasture or range land to
prevent soil loss and allow water to infiltrate. Sometimes used in planting trees or
shrubs on the contour.
Contour interval: The vertical distance between contour lines.
Contour ploughing: A soil conservation technique involving ploughing parallel to the
contour, across a slope rather than up and down it.
Contour strip cropping: The production of crops in comparatively narrow strips
planted on the contour and at right angles to the natural direction of slope. Usually
strips of grass or close growing crops are alternated with those in cultivated crops.
Contour: An imaginary line connecting points of equal elevation on the surface of the soil.

Glossary
Rainfed Agriculture and Watershed Management: Mevada K. D., Poonia T. C, Saras Piyush and Deshmukh S.P. Page iii
Cover crop: A close growing crop grown primarily for the purpose of protecting and
improving soil between periods of regular crop production, or between trees and
vines in orchards and vineyards.
Cover, ground: Any vegetation production a protecting 'mat on or just above the soil
surface. In forestry, low-growing shrubs and herbaceous plants under the trees.
Creep: Slow mass movement of soil and soil material down relatively steep slopes
primarily under the influence of gravity, but facilitated by saturation with water and by
alternate freezing and thawing.
Crop rotation: The growing of different crops in recurring succession on the same
land.
Deciduous forest: A forest composed of trees that shed their leaves at some season of the
year. In tropical areas trees may lose their leaves during the hot season to conserve moisture.
Trees of a deciduous forest in cool areas shed their leaves during the autumn to protect
themselves against the cold and frost of winter. Deciduous forests produce valuable
hardwood timber, such as teak and mahogany from the tropics, and oak and beech from the
cooler areas.
Deflation: Process where wind erosion creates blowout depressions or deflation hollows by
removing and transporting sediment and soil.
Dendrology: The study of trees, that is, a knowledge of the taxonomy, systematic
relationships and field recognition of tree species.
Dendrometer: A device for measuring the diameter of the trunk or branch of a tree.
Depression storage: Water in puddles, small ponds and depressions.
Detention dam: A dam constructed for the purpose of temporary storage of stream
flow, or surface runoff, and for releasing the stored water at controlled rates.
Dike: An embankment to confine or control water, especially one built along the
banks of a river to prevent overflow of lowland; a levee.
Disperse: To distribute or suspend fine particles, such as clay, in or throughout a
dispersion medium, such as water.
Diversion dam: A structure or barrier built to divert part or all of the water of a
stream to a different course.
Diversion: A diversion is a channel with a supporting ridge on the lower side
constructed across the slope to intercept runoff and minimize erosion, or to prevent
excess runoff from flowing into lower lying areas. In some areas a series of
diversions are constructed across the slope similar to terraces, but with greater
horizontal and vertical spacing. Also known as diversion terrace.
Drag: The force retarding the flow of water or wind over the surface of the ground.
Drainage area: An area whose runoff is more or less separate from the runoff of
adjacent areas, so that it can be considered a hydrologic unit.
Drainage divide: The boundary line, along a topographic ridge or along a sub-
surface formation, separating two adjacent drainage basins.
Drainage: The frequency and duration of periods when the soil is free of saturation with
water.
Drift: Material of any sort deposited in one place after having been moved from
another. The term is most commonly used when referring to glacial drift.

Glossary
Rainfed Agriculture and Watershed Management: Mevada K. D., Poonia T. C, Saras Piyush and Deshmukh S.P. Page iv
Drop structure: A dam constructed in a gully or other water course to lower the
grade of the water course and thereby decrease the velocity of flow, promote the
deposition of sediment, and prevent further channel erosion.
Dryland farming: The practice of crop production in low rainfall areas without
irrigation.
Dune: A mound or ridge of loose sand piled up by the wind; common where sand is
abundant and wind usually strong as along lake and sea shores and in some desert
and semi-desert areas.
Dust mulch: A loose, finely granular, or powdery condition on the surface of the soil
usually produced by shallow cultivation.
Edaphic: Of or pertaining to the soil in its ecological relationships. Resulting from, or
influenced by, factors inherent in the soil or other substrate rather than by climatic factors.
Effective precipitation: That portion of the total precipitation which becomes
available for plant growth.
Eluviation: The transportation of soil material in suspension, or in solution within the soil,
by the downward or lateral movement of water.
Energy Farming: The process of using land to grow crops, woody or otherwise, that provide
fuel, for example, close-planted, fast-growing tree species such as poplar (temperate) or
leucaena (tropical). These may be harvested by hand or mechanically. Hydrocarbon fuels can
be extracted from other kinds of plants, for example, from some Euphorbia species.
Enriched fallow: A form of agroforestry in which useful, mainly woody species are sown or
planted before cultivation ceases, or at the time it does, so that during the fallow period, or
when the land is next cleared for cultivation, products are available for household use or
market that would not otherwise have been there (for example, fruits, bamboos, rattans,
medicinals).
Entrainment: One of three distinct processes involved in erosion. More specifically, it is the
process of particle lifting by an agent of erosion.
Erode: To wear away or remove the land surface by wind, water, or other agents.
Erodibility: Susceptibility to erosion, erosion proneness.
Erodible: Susceptible to erosion.
Erosion pavement: A layer of coarse fragments, such as sand or gravel, remaining
on the surface of the ground after the removal of fine particles by erosion.
Erosion: (i) The wearing away of the land surface by running water, wind, ice or
other geological agents, including such processes as gravitational creep; (ii)
Detachment and movement of soil or rock by water, wind, ice, or gravity.
Erosive: Tending to cause erosion; the term applies to the eroding agent, such as
wind or water.
Erosivity: Potential ability of physical dynamic agents such as water, wind or ice to cause
erosion.
Estuary: Somewhat enclosed coastal area at the mouth of a river where nutrient rich fresh
water meets with salty ocean water.
Eutrophication: Nutrient enrichment of lakes, ponds, and other such waters that stimulates
the growth of aquatic organisms, which leads to a deficiency of oxygen in the water body.
Fallow: Allowing crop land to lie idle, either tilled or untilled, during the whole or greater
portion of a growing season. Tillage is usually practiced to control weeds and encourage the

Glossary
Rainfed Agriculture and Watershed Management: Mevada K. D., Poonia T. C, Saras Piyush and Deshmukh S.P. Page v
storage of moisture in the soil. Land rested from deliberate cropping, not necessarily without
cultivation or grazing but without sowing.
Felling: Cutting trees for their removal.
Field border plantings: Vegetation establishment on field borders to conserve soil
and provide cover and food for wildlife.
Field strip cropping: A system of strip cropping in which crops are grown in parallel
strips laid out across the general slope but which do not follow the contour. Strips of
grass or close-growing crops are alternated with those in cultivated crops.
Filter strip: A strip of permanent vegetation of sufficient width and vegetative density
above farm ponds, diversion terraces and other structures to retard flow of runoff
water, causing it to deposit soil, thereby preventing silting of structure or reservoir
below.
Firebreak: In forestry, an existing barrier, or one constructed before a fire occurs, from
which flammable materials have been removed, designed to stop or check creeping or
running fires. Also serves as a line from which to work and to facilitate the movement of men
and equipment in fire suppression.
Flood plain: The land bordering a stream, built up of sediments from overflow of the
stream and subject to inundation when the stream is at flood stage.
Geological erosion: The normal or natural erosion caused by geological processes
acting over long geologic periods and resulting in the wearing away of mountains,
the building up of flood plains, coastal plains, etc.
Glacial drift: Rock debris that has been transported by glaciers and deposited,
either directly from the ice or from the melt-water. The debris mayor may not be
heterogeneous.
Glacier: A large long lasting accumulation of snow and ice that develops on land. Most
glaciers flow along topographic gradients because of their weight and gravity.
Gley: Soil with impeded drainage. Used in soil classifications based on profile leaching.
Graded terrace: A terrace having a constant or variable grade along its length.
Grassed waterway: A natural or constructed waterway, usually broad or shallow,
covered with erosion-resistant grasses, used to conduct surface water from crop
land.
Grassland: Land covered with grasses and other herbaceous species. Woody plants may be
present, but if so, they do not cover more than 10% of the ground. There are many different
types of grassland designated by ecozone, topography, climate, soil conditions, and so on.
Derived grassland is maintained in that condition by regular burning; edaphic grassland arises
on particular soil types, for example, those found in or around permanent or seasonal
swamps.
Grazing: A method of feeding by herbivores characterized by repeated removal of only a
part, generally the leaf, of the plant, which is most commonly called herbage.
Groundwater basin: A groundwater storage area more or less separate from
neighbouring groundwater storage areas, so that it can be considered a hydrologic
unit.
Groundwater: The general sub-surface water body in the zone of saturation.
Grubbing: Felling trees and shrubs by exposing and cutting the roots.

Glossary
Rainfed Agriculture and Watershed Management: Mevada K. D., Poonia T. C, Saras Piyush and Deshmukh S.P. Page vi
Gully erosion: The erosion process whereby water accumulates in narrow channels
and, over short periods, removes the soil from this narrow area to considerable
depths, ranging from 30 to 60 cm as much as 22.5 to 30 cm.
Gully: A channel resulting from erosion and caused by the concentrated, but
intermittent, flow of water usually during and immediately following heavy rains. Deep
enough to interfere with, and not to be obliterated by, normal tillage operations.
Hedge row: A barrier of bushes, shrubs, or small trees growing close together in a
line.
Infiltration: The downward entry of water into the soil.
Interpolated cropping: A cropping sequence where two or more species are grown on the
same unit of land but at least one species has a later sowing (planting) time and an earlier
harvest than the other(s). Refers to situations where the crop duration of species is very
different.
Land capability classification: The arrangement of land units into various categories based
upon the properties of the land or its suitability for some particular purpose.
Land capability: The suitability of land for use without damage. Land capability
involves consideration of (a) the risks of land damage from erosion or other causes
and (b) the difficulties in land use owing to physical land characteristics including
climate.
Landscape: All the natural features such as fields, hills, forests, water etc. which
distinguish one part of the earth's surface from another part. Usually that portion of
land or territory which the eye can comprehend in a single view, including all its
natural characteristics.
Landslide: A mass of material which has slipped down hill under the influence of
gravity, frequently assisted by water (when the material is saturated).
Leaching: The washing out of material from the soil, both in solution and in suspension.
Level terrace: A terrace that follows the absolute contour as contrasted with a
graded terrace. Used only on permeable soils where conservation of moisture for
crop use is particularly important or where outlet channels are impractical.
Ley farming: Rotation of arable crops with two or more years of sown pasture.
Ley pasture: A temporary pasture grown as a specific phase in a defined crop rotation
sequence.
Loess: Deposit of wind-transported fine-textured material, uniform and unstratified,
mostly silt, but may contain some fine sand and clay.
Lopping: Cutting one or more branches of a standing tree, for example, for fuel or fodder.
Mangroves: Open or closed stands of trees and bushes occurring in the tropics in intertidal
zones, usually around the mouths of rivers, creeks and lagoons where soils are heavy textured
and have a fluctuating salt content and soil level.
Meadow strip: A sloping field or strip of grassed land which, in addition to yielding a
hay crop, acts as a broad shallow water channel during periods of runoff. Often used as a
terrace outlet channel and usually much larger in extent than a grassed water way.
Mulch farming: A system of farming in which the organic residues are not ploughed
into or otherwise mixed with the soil but are left on the surface as a mulch.

Glossary
Rainfed Agriculture and Watershed Management: Mevada K. D., Poonia T. C, Saras Piyush and Deshmukh S.P. Page vii
Mulch: Any material such as straw, sawdust, leaves, plastic film, loose soil etc. that
is spread upon the surface of the soil to protect the soil and plant roots from the
effects of rain drops, soil crusting, freezing, evaporation etc.
Multipurpose tree: A woody perennial purposefully grown to provide more than one
significant contribution to the production or service functions (for example, shelter, shade,
land sustainability) of the land-use system that it occupies.
Natural erosion: Wearing away of the earth's surface by water, ice, or other natural
agents under natural environmental conditions of climate, vegetation, etc.
undisturbed by man.
Niche: A place or position adapted to the character, or suited to the merit, of a person or
thing. The sum total of adaptations of an organismic unit. In ecology, the total range of
conditions under which the individual (or population) lives and replaces itself, or the position
or status of an organism within its community and ecosystem resulting from the organism's
structural adaptations.
Normal erosion: The gradual erosion of land used by man which does not greatly
exceed natural erosion.
Overland flow: Flow of water over the land surface as sheet flow not in channels.
Parent material: The horizon of weathered rock or partly weathered soil material
from which the soil is formed.
Pasture improvement: Any practice of grazing, moving, fertilizing, liming, seeding,
scattering droppings, contour furrowing, or other methods of management designed
to improve the vegetation for grazing purposes.
Pasture: In U.S. terminology, land on which the natural vegetation is not grass, but which is
used primarily for grazing.
Percolation: The downward movement of water through soil.
Productivity: The capacity of a soil in its normal environment, for producing a
specified plant or sequence of plants under a specified system of management.
Productivity emphasized the capacity of soil to produce crops and should be
expressed in terms of yields.
Rainforest: Generally, a forest that grows in a region of heavy annual precipitation. There
are both tropical and temperate rainforests.
Range management: The scientific management of range land for the continuous
production of forage and livestock, consistent with the use of the land for other
purposes.
Range: Land that produces primarily native forage suitable for grazing by livestock.
Rangeland: Land that provides or is capable of providing forage for grazing animals.
Reach: A specific portion of the length of a stream channel.
Reforestation: Replacing forests after felling.
Relief: The relative differences in elevation between the upland summits and the lowlands or
valleys of a given region.
Resilience: The capacity of a soil (or other ecosystem) to return to its original state after a
disturbance.
Ridge terrace: A long, low ridge of earth with gently sloping sides, and a shallow
channel along the upper side, to control erosion by diverting surface runoff across

Glossary
Rainfed Agriculture and Watershed Management: Mevada K. D., Poonia T. C, Saras Piyush and Deshmukh S.P. Page viii
the slope instead of permitting it to flow uninterrupted down the slope. Types of ridge
terraces include the broad base, drainage, grades level, narrow base etc.
Rill erosion: An erosion process in which numerous small channels of only several
centimetres in depth are formed; occurs mainly on recently cultivated soils.
Rill: A small, intermittent water course with steep sides; usually only a few
centimetres to deep and, hence, no obstacle to tillage operations.
Riparian forest: Vegetation, with trees and shrubs, growing alongside or close to a
watercourse, lake, swamp, or the like, and often dependent on its roots reaching the
watertable.
River wash: Barren alluvial land, usually coarse-textured, exposed along streams at
low water and subject to shifting during normal high water. A miscellaneous land type.
Riverine: An environment created along permanent and semi-permanent streams because of
the increase in soil moisture. This is termed a riverine environment.
Rotational grazing: Grazing systems in which the pasture is subdivided into a number of
enclosures, with at least one more of these than there are groups of animals. The practice of
submitting a grazing area to a regular sequence of grazing alternating with rest.
Runoff: Runoff is that part of precipitation, snow or ice melt or irrigation water that flows
from the land to the streams or other water surfaces. The portion of the precipitation on an
area that is discharged from the area through stream channels. That which is lost without
entering the soil is called surface runoff and that which enters the soil before reaching the
stream is called groundwater runoff or seepage flow from groundwater. (In soil science runoff
usually refers to the water lost by surface flow; in geology and hydraulics runoff usually
includes both surface and subsurface flow).
Sediment: Fragmented organic or inorganic material derived from the weathering of soil,
alluvial, and rock materials; removed by erosion and transported by water, wind, ice, and
gravity.
Sedimentation: The deposition of sediment from a state of suspension in water or air.
Sheet erosion: The removal of a fairly uniform layer of soil from the land surface by
runoff water.
Shelterbelt: An extended wind break of living trees and shrubs established and
maintained for protection of farm lands over an area larger than a single farm.
Silting: The deposition of water-borne sediments in stream channels, lakes,
reservoirs, or on flood plains, usually resulting from a decrease in the velocity of the
water.
Slash: In forestry, the vegetation (branch and other woody and leafy debris) left on the forest
floor after trees have been felled or trimmed.
Slope: The degree of deviation of a surface from horizontal, measured in a numerical ratio,
percent, or degrees.
Social forestry: The planting and tending of trees or shrubs for the well-being and betterment
of local communities.
Spillway: A conduit in or around a dam for the escape of excess water.
Splash erosion: The spattering of small soil particles caused by the impact of
rain drops on very wet soils. The loosened and spattered particles mayor may not be
subsequently removed by surface runoff.
Spur terrace: A short terrace used to collect or divert runoff.

Glossary
Rainfed Agriculture and Watershed Management: Mevada K. D., Poonia T. C, Saras Piyush and Deshmukh S.P. Page ix
Stream gaging: The collection of stream-flow data by direct measurements of
discharge and water surface elevations.
Strip cropping: The practice of growing crops which require different types of
tillage, such as row and sod, in alternate strips along contours or across the
prevailing direction of wind.
Stubble mulch: The stubble of crops or crop residues left essentially in place on the
land as a surface cover before and during the preparation of the seedbed and at
least partly during the growing of a succeeding crop.
Surface sealing: The orientation and packing of dispersed soil particles in the immediate
surface layer of the soil, rendering it relatively impermeable to water. j
Terrace: A raised, more or less level or horizontal strip of earth usually constructed on or
nearly on a contour and supported on the downslope side by rocks or other similar barrier and
designed to make the land suitable for tillage and to prevent
accelerated erosion.
Through fall: The proportion of the gross precipitation that reaches the ground and is not
intercepted by, or retained in, the canopy.
Tie ridging: In contour furrowing or trenching, a narrow transverse strip of ground left
unexcavated (or ridged).
Wasteland: Land not suitable for, or capable of, producing materials or services of
value.
Water harvesting: A general term for any means of collecting and re-distributing runoff
water.
Watershed: The total land area, regardless of size, above a given point on a
waterway that contributes runoff to the flow at that point.
Waterway: A natural course for the flow of water.
Weir: A dam across a stream for diverting or for measuring the flow.
Windbreak: A planting of trees, shrubs or other vegetation, usually perpendicular or
nearly so to the principal wind direction, to protect soil, crops, homesteads, roads
etc. against the effects of winds, such as wind erosion and the drifting of soil and
snow. A group of trees or shrubs in any arrangement that will afford protection from high
winds to animals or crops or both. When the arrangement is in a long line the group is called
a shelterbelt. If an associated reason is also to harvest timber at some future date it is
sometimes called a 'timberbelt'.
Wind erosion: The detachment, transportation and deposition of soil by the action of
wind.
Wind strip cropping: The production of crops in long, relatively narrow strips, placed cross
wise of the direction of the prevailing winds without regard to the contour of the land.
Zero-grazing: A method of keeping animals that involves bringing fodder to them rather
than letting the animals graze freely.

Glossary
Rainfed Agriculture and Watershed Management: Mevada K. D., Poonia T. C, Saras Piyush and Deshmukh S.P. Page x
ABBREVIATIONS
AICRPDA : All India Coordinated Research Project on Dryland Agriculture, Hyderabad
AISSLUP : All India Soil Survey and Land Use Planning, New Delhi
CADA : Command Area Development Authority
CAZRI : Central Arid Zone Research Institute, Jodhpur
CRIDA : Central Research Institute for Dryland Agriculture, Hyderabad
CSWCRTI : Central Soil & Water Conservation Research & Training Institute, Dehradun
DDP : Desert Development Programme
DPAP : Drought Prone Area Programme
ICARDA : International Centre for Agriculture Research on Dry Areas, Aleppo, Syria
ICRAF : International Centre for Research on Agroforestry, Nairobi, Kenya
ICRISAT : International Crops Research Institute for the Semi-Arid Tropics, Hyderabad
IFOAM : International Federation for Organic Agricultural Movements
IGFRI : Indian Grassland and Fodder Research Institute, Jhansi
IPCC : Intergovernmental Panel on Climate Change
IREP : Integrated Rural Energy Programme
IWDP : Integrated Wasteland Development Project
LCC : Land Capability Class
NBSS & LUP: National Bureau of Soil Survey and Land Use Planning, Nagpur
NRCAF : National Research Centre for Agroforestry, Jhansi
NRSA : National Remote Sensing Agency, Hyderabad
NWDB : National Wasteland Development Board, New Delhi
NWDPRA : National Watershed Development Programme for Rainfed Areas
RADAS : Reclamation & Development of Alkali and Acid Soil
RVP & FPR : River Valley Project & Flood Prone River
UNCED : United Nations Conference on Environment and Development
WALAMTARI : Water and Land Management Training Research Institute
WDF : Watershed Development Fund
WDPSCA : Watershed Development Project for Shifting Cultivation Area

1
Reference Books:
1. Principles of Agronomy, T. Yellamanda Reddy and G.H. Sankara Reddi
2. Principles of Agronomy, S R Reddy
3. Watershed Management, V.V. Dhruva Narayana, G. Sastry and U. S. Patnaik
4. Principles of Crop Production, S R Reddy
5. Sustainable Dryland Farming, Arvind M Dhopte
6. Fundamentals of Watershed Management, Singh G. D. & Poonia T. C.
7. Principles and Practices of Dryland Agriculture, K. Govindan & V. Thirumuruan
8. Dry Farming for Sustainable Agriculture, John A. Widtsoe
9. Watershed Management for Sustainable Agriculture, M. A. Khan
10. Rainfed Farming, M. L. Jat, J.K. Balyan, A.K. Kothari and L. K. Jain

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