Last updated on August 29th, 2024 Posted on August 29, 2024 by NEXT IAS Team 1993
India’s different types of irrigation encompass various methods suited to various environmental conditions and water availability. Understanding these irrigation types is crucial for optimising water use, improving crop yields, and adapting to regional climatic and topographical variations. This article aims to study in detail the various irrigation methods used across India, their regional adaptations, and their impact on agricultural productivity.
About Irrigation System in India
Irrigation is crucial in sustaining agriculture in India, especially given the country’s variable and unpredictable monsoon patterns.
The diverse topography and climatic conditions across India have led to the development of various irrigation methods, each tailored to the specific needs of different regions.
These irrigation systems help ensure a consistent water supply to crops, supporting the agricultural economy and food security.
The primary irrigation methods encompass wells and tube wells, canals, tanks, traditional water harvesting techniques, and micro irrigation.
Traditional irrigation types include various irrigation practices in rural India that have been practised for ages. Some of them are famous by names such as Johars, Baolis, Hundu, Suragam, Kuhls, Sprins, and Doug.
Type of Irrigation Project
Culturable Command Area
Major projects
>10,000 hectares
Medium project
2000 to 10,000 hectares
Minor project
< 2000 hectares
Canal Irrigation
Canal irrigation is a key irrigation method, contributing approximately 24% of the total irrigation in India.
It is particularly effective in areas with low relief, fertile soil, and access to perennial rivers.
As a result, canal irrigation is predominantly concentrated in the northern plains.
Currently, about 16.5 million hectares are irrigated by canals in India, with 60% of this area located in northern states like Uttar Pradesh, Punjab, Haryana, Bihar, and Rajasthan.
Tank Irrigation
A tank is a water storage system created by constructing a small bund of earth or stones across a stream.
The water captured by this bund is used for irrigation and other purposes. Tanks are typically small and built by individual farmers or groups.
The proportion of land irrigated by tanks has decreased from 14% in 1960-61 to 3% in 2010-11, largely due to the rise in well and tube well irrigation and a decline in tank irrigation.
Andhra Pradesh, Telangana, and Tamil Nadu are the leading states in tank irrigation, with Tamil Nadu contributing 23% and Andhra Pradesh and Telangana together accounting for 28% of the total.
The drainage area of Godavari and its tributaries have a large number of tanks. Nellore and Warangal are the main districts where tank irrigation is done.
Reasons for the Presence of Tank Irrigation System in Peninsular India
Undulating relief and hard rock make it challenging to dig canals and wells.
Little percolation of rainwater due to the hard rock structure, and groundwater is not available in large quantities.
Most rivers in this region are seasonal and dry up during the summer, which means they cannot provide a continuous water supply to canals throughout the year.
Several streams become torrential during the rainy season. The only way to make the most of them is to impound them by constructing bunds and tanks.
The scattered nature of the population and agricultural fields necessitates tank irrigation.
Merits and Demerits of Tank Irrigation
Merits
Demerits
They are natural, so no heavy construction cost is involved.
Many tanks dry up in the dry season and fail to provide water when needed.
Even an individual farmer can have his tank.
Tank requires regular de-silting.
Tanks are generally constructed on rocky beds and have a longer period.
Much of the water evaporated due to the large tank expanse leading to the shallow tanks.
Fishing activity from tank supplements food and additional income requirements of farmers.
Tanks cover a large area of cultivable land (in many areas, other sources of irrigation are adopted, and dry beds of tanks are reclaimed for agriculture).
Land near the tank can be utilised for agriculture.
Lifting up water from tanks and carrying it to the field is a costly exercise.
The tank can be easily managed at the panchayat level.
Often, disputes arise regarding the utilization of water during the summer season.
Wells
A well is a hole excavated in the ground to access subsoil water. Typical wells are approximately 8 to 12 meters deep, while deeper wells can reach around 15 meters.
Several methods, such as the Persian wheel, Reht, Charas, or Mot, and Dhingly (Leather Bay method), lift ground water from wells.
Geographical Distribution of Wells and Tubewells
Well and Tube well irrigation accounts for about 62% of the net irrigated area in the country.
There has been a sixfold increase in well irrigation since 1950. Popular areas with sufficient sweet groundwater are:
Northern Plains,
Deltaic plains of Mahanadi, Godavari, Krishna, Cauvery,
Parts of Narmada and Tapi Valleys,
Weathered areas of Deccan trap,
Crystalline and sedimentary zone of peninsular India.
Greater parts of peninsular India are unsuitable for well irrigation because of their uneven surfaces, rocky structures, and lack of groundwater.
A vast arid region in Rajasthan, along with adjacent areas in Punjab, Haryana, Gujarat, and parts of Uttar Pradesh, contains brackish underground water unsuitable for irrigation, human consumption, or agricultural use.
Uttar Pradesh has the largest area under well irrigation in the country, covering 23% of the nation’s total. Following Uttar Pradesh are Rajasthan with 10%, Punjab with 8%, Madhya Pradesh with 7.9%, Gujarat with 7.3%, and Bihar with 6.2%.
Tube Wells
A tube well is a deep well (over 15 meters) that uses a pumping system powered by an electric motor or diesel engine to lift water. Ideal conditions for installing tube wells include:
Adequate groundwater supply: A tube well can irrigate up to 2 hectares per day, compared to 0.2 hectares per day by an ordinary well.
High groundwater table: The water table should be less than 15 meters deep for pumping to remain cost-effective; deeper levels make pumping less economical.
A regular supply of cheap electricity and diesel so water can be removed when needed.
The soil in the immediate vicinity of the tube well should be fertile, and increased farm production will recover the construction and operational costs of the tube well.
Following the Green Revolution, the use of tube wells rose in Punjab, Haryana, and Western Uttar Pradesh. In well and tube well irrigation, water application efficiency is 60%.
Merits and Demerits of Well and Tube Well Irrigation
Merits
Demerits
Tube well irrigation is simplest and cheapest source of irrigation for poor Indian farmers.
Only a limited area can be irrigated. Normally a well can irrigate 1 to 8 hectares of land.
Tube well irrigation has independent of irrigation agencies and can be used as and when necessary arises.
Well may dry up due to excessive use and render useless when needed for irrigation.
Note: Tamil Nadu has the highest number of tube wells, followed by Maharashtra, Andhra Pradesh, and Uttar Pradesh.
Micro Irrigation
Micro-irrigation is considered a prudent Irrigation technology promoted nationally and internationally to achieve higher cropping and irrigation Intensities through more focused water application to crops.
The average penetration of micro-irrigation in India is 19% as of 2021.
Micro-irrigation involves two methods of irrigation system.
Drip Irrigation
In drip irrigation, water is delivered near the plant roots through emitters or drippers positioned on or below the soil surface at a low rate, ranging from 2 to 20 litres per hour.
This method maintains optimal soil moisture with frequent, controlled applications.
Advantages of Drip Irrigation
Disadvantages of Drip Irrigation
Soil erosion is lessened.
The initial cost can be higher in this technique.
Weed growth is lessened. Soil type plays a less critical role in the frequency of irrigation.
In lighter soils, the subsurface drip may not be able to wet the soil surface for germination. This requires careful consideration of the installation depth.
Water distribution is highly uniform and controlled by the output of each nozzle.
Drip tape causes extra clean-up costs after harvest. Users must plan for drip tape winding, disposal, recycling or reuse.
Plants remain dry, reducing the risk of disease.
Drip irrigation might be inadequate if herbicides or top-dressed fertilisers need sprinkler irrigation for activation.
Water application efficiency is high.
If the water is not properly filtered and the equipment is not suitably maintained, it can result in blockage.
Sprinkler Irrigation
In this method, water is sprayed into the air and allowed to fall onto the ground, mimicking the effects of rainfall.
The spray is developed by water flow under pressure through small orifices or nozzles.
The sprinkler irrigation system is suitable for irrigating uneven lands and shallow soils.
Other Types of Irrigation System in India
Furrow Irrigation: Furrow irrigation is a surface irrigation method where trenches, or “furrows,” are dug between rows of crops in a field.
Farmers flow water down the furrows, seeping vertically and horizontally to refill the soil reservoir.
Flow to each furrow is individually controlled.
Furrow irrigation is mainly used in maize, sunflower, sugarcane and soybean cultivation.
Surge Irrigation: Surge irrigation is an advanced form of furrow irrigation in which the water supply is alternately turned on and off at scheduled intervals. This pulsed approach creates wetting and drying cycles, which reduces infiltration rates and results in faster water movement and more uniform distribution compared to continuous flow methods.
Ditch Irrigation: In ditch irrigation, traditional ditches are dug, and seedlings are planted in rows. Water is supplied through canals or furrows placed between the rows, with siphon tubes transferring water from the main ditch to the smaller channels.
Subirrigation: Subirrigation, also known as seepage irrigation, delivers water to the plant root zone from below the soil surface, allowing it to be absorbed upward to nourish the plants.
Conclusion
India’s irrigation systems are essential for sustaining agriculture and adapting to diverse climatic and geographical conditions. Traditional methods like tank and well irrigation and modern techniques such as micro-irrigation address specific regional needs. As water scarcity and climate challenges intensify, integrating these practices will be vital in enhancing agricultural productivity and ensuring food security for the future.
Frequently Asked Questions (FAQs)
What are the 4 types of irrigation?
The four main types of irrigation are: – Surface Irrigation – Drip Irrigation – Sprinkler Irrigation – Subsurface Irrigation
