Irrigation: Meaning, Types, Methods and Importance

Irrigation: Irrigation is the artificial and controlled application of water to soil, plants, or agricultural fields in order to meet their water needs. It ensures optimal moisture levels for plant growth, increases crop yield and sustains agricultural activities in regions with inadequate or unpredictable rainfall. India has the world's largest irrigated land, with around 85 percent of total irrigation potential currently developed.

What is Irrigation?

The artificial application of water to the soil or agricultural land which fulfills the demand for water is known as Irrigation.

It is the process of replacing or supplementing rainwater with water from another source. It is utilized in dry places and when rainfall is insufficient. It enables farmers to produce crops in areas with low or irregular rainfall, increasing food security and economic stability. Irrigation systems are designed to aid in the growth of agricultural crops and plants by using the least amount of water possible, preventing soil consolidation, and so on. Irrigation frequency, rate, amount, and time differ for different crops, as well as soil types and seasons. Summer crops, for example, demand far more water than winter crops. However, overirrigation can lead to problems like waterlogging, salinization, and environmental degradation. Therefore, sustainable and efficient irrigation practices are essential to ensure long-term agricultural productivity and environmental balance.

Also, read: Fertilizers, and Manures

Types of Irrigation

Irrigation can be done by different methods and on the basis of the pattern followed for the irrigation. Irrigation depends upon the climate, resources, crops, and surroundings. Irrigation is divided into different types:

Surface Irrigation

In surface irrigation water is applied directly to the soil surface and allowed to flow over the field by gravity. This irrigation is done manually, with no involvement of any machine. It's one of the oldest and simplest methods of irrigation. Surface irrigation is further divided into 3 types:

1. Furrow Irrigation: It involves creating small channels or furrows along the field's contour, allowing water to flow down the furrows and infiltrate the soil around the plants' root zones. This method is suitable for row crops and orchards. If not done properly it can lead to uneven water distribution and potential soil erosion.
2. Basin Irrigation: It involves creating shallow depressions or basins around individual plants or groups of plants. Water is then applied directly into these basins, allowing it to gradually seep into the soil around the plants. Such types of irrigation are normally done in small layout fields.
3. Border Irrigation: Border irrigation involves dividing a field into long, narrow strips called borders, which are then bordered by low ridges to contain water. Water is released at the higher end of the border, and it flows by gravity across the strip, irrigating the plants along its path

Localized Irrigation

It is also known as Micro Irrigation. Localized irrigation systems apply water directly to the root area of individual plants, reducing water loss from the soil through evaporation. It reduces water wastage, reduces evaporation, and weed growth. The network of pipes provides water evenly to the plants under low pressure. Drip irrigation, porous clay pots, porous pipes, and perforated plastic sleeves are examples of localized irrigation methods. It is a very efficient method because it provides the optimum amount of water to the plants or crops at regular intervals of time.

Sprinkler Irrigation

With the help of a pump, a sprinkler irrigation system apply water under high pressure. It uses a small diameter nozzle in the pipes and distributes it in the form of small water droplets that resembles rain. Due to the wide range of discharge capacity, water is spread through a system of pipes, sprayed into the air, and irrigate the area. This method is commonly used in agriculture, landscaping, and sports field maintenance.

Drip Irrigation

Drip irrigation is the most effective technique for providing water and nutrients to crops with less amount of water loss. This method involves the controlled release of water through a network of pipes, tubes, and emitters placed near or within the soil. It provides water and nutrients directly to the root area of the plant in precise amount and at specific time, ensuring that each plant receives exactly what it requires, when it requires it, for optimal growth.

Centre Pivot Irrigation

Center-pivot irrigation, also known as water-wheel or circle irrigation, is a mechanized method of irrigating large agricultural fields in a circular pattern. It uses a rotating system of pipes and sprinklers mounted on wheeled towers, with a central pivot point that delivers water to crops as the equipment moves in a circular path around the pivot point. It allows for precise control of water application based on factors like crop needs and weather conditions and requires less manual labor compared to traditional irrigation methods.

Sub Irrigation

Sub-irrigation also known as subsurface irrigation or seepage irrigation. In this method water is provided to plants by delivering it directly to the root area from below the soil surface. It uses capillary action to allow controlled movement of water. The water is directly absorbed through the roots.

Manual Irrigation

As the name suggests it can be done by anyone who is physically capable. Manual irrigation is by far the most common kind of irrigation. The farmer circulates water from the plant to the plant with manual irrigation. This requires a lot of effort and time, and it's usually done with a hose or bucket. It is suitable for small areas.

Methods of Irrigation

Irrigation methods can be of 2 types on the basis of how the irrigation process takes place.

• Traditional Methods of Irrigation
• Modern Methods of Irrigation

Traditional Methods of Irrigation

In the traditional method, irrigation is done by man's force or with the help of animals. A farmer takes water from wells or canals by hand or with the help of livestock and transports it to farming areas. At different places, this procedure may differ that is according to geographic, climatic, and cultural conditions. The key benefit of this method is its low cost. However, productivity is low, as there is more water loss and uneven distribution of water. Pulley systems, lever systems, and chain pumps are examples of traditional systems. The pump system is the most commonly used method.

Modern Methods of Irrigation

The current method compensates for the shortcomings of traditional systems. It improved water efficiency, crop productivity, and sustainability. This method utilizes modern equipment, technology approaches to optimize water distribution. Sprinkler and drip systems are utilized in a current manner.

Sprinkler System

A sprinkler system distributes water over the crop to ensure even distribution. In areas where water is scarce, this method is highly recommended. A pump connected to pressure-generating pipes sprays water through the nozzles of pipes.

Drip System

The drip system delivers water to the roots one drop at a time through a hose or pipe. This approach can also be employed in areas where there is a scarcity of water.

Comparison of Traditional Irrigation vs Modern Irrigation

The difference between Traditional and Modern Irrigation are as follows:

Importance of Irrigation

The importance of Irrigation is as follows:

1. Agriculture suffers from insufficient and unpredictable rainfall. Low rainfall results in droughts and famines.
2. In comparison to unirrigated land, irrigated land has better productivity.
3. Multiple cropping is not viable in India because most locations have their own rainy season. The climate, on the other hand, favors cultivation all year.
4. Irrigation has aided in the cultivation of the majority of the fallow land.
5. Irrigation has helped to stabilize output and yield levels.
6. Irrigation increases water supply availability, which increases crop yield.

Irrigation should be done ideally, over-irrigation negatively affects the crop and also impact the crop productivity and damage the crop. Overflow of water in crops causes waterlogging in the field which causes an increase in the salt concentration, and the growth of roots upward. So for better results, irrigation should be done under ideal conditions.

Challenges of Irrigation

Irrigation forms an important part of agriculture but faces several challenges that need to be addressed to ensure sustainable water use, environmental conservation, and food security. Some of the key challenges of irrigation are as follows:

• Excessive groundwater pumping for irrigation can lead to the depletion of aquifers, causing water tables to drop and land to subside.
• Water resources are limited and face increasing competition from urban, industrial, and other agricultural sectors.
• Over-irrigation and poor water management can lead to the degradation of ecosystems, loss of biodiversity, and disruption of natural hydrological cycles.
• Proper maintenance of irrigation infrastructure is essential for effective water delivery.
• Improper irrigation practices can lead to waterlogging, salinization, and accumulation of pollutants in soil and water bodies.

Also, read: Crop Improvement