India is one of the largest users of freshwater in the world and the majority of this water (90.4%) is used for agriculture. A good monsoon means a bountiful harvest for India’s farmers. In addition to rainwater, India’s farmers also depend on water from rivers, canals, reservoirs, springs and wells for irrigating their crops.

To prevent the overuse of water for agriculture, the Indian government has been promoting micro irrigation for years.

What is micro irrigation?

Micro irrigation is a method where plants are slowly watered from above or below the soil through drops, tiny streams, spray or mist, either continuously or at intervals. This is done over a long period of time. In this method, water is released at a low pressure and a low flow rate which ensures that only the required amount of water is given to a field, preventing overwatering.

Although micro irrigation is a modern farming technology that was developed in the U.S., Europe and Israel, it has also been practised historically in India. The indigenous communities in Meghalaya have been using a bamboo drip irrigation system for over 200 years. In this method, hollow bamboo trunks and smaller bamboo shoots are joined with twine to form a zig-zag pipeline structure that connects a water source uphill, such as a steam or spring, to a terraced field downhill. Holes are made in the shoots so that water can reach crops drop by drop. This irrigation system is used for growing rice, betel leaf and pepper in the dry months.

“Drip irrigation and sprinkler irrigation systems were introduced and have been operational in India since the 1970s,” said Kamlesh Narayan Tiwari, former professor at Indian Institute of Technology, Kharagpur. Tiwari has worked extensively on developing new micro irrigation technologies and currently teaches an online course on micro irrigation engineering through the National Programme on Technology Enhanced Learning (NPTEL), run by the Ministry of Education.

In India, where surface or flood irrigation is the norm, some farmers use micro irrigation, though the number is still small. According to reports, of the 141 million hectares of gross sown area in the country, nearly 52% or 73 million hectares had irrigation access as of 2022-23. Micro irrigation facilities were installed in just 11% or 8 million hectares of the total irrigation infrastructure. Currently, the top five states using micro irrigation are Karnataka, Tamil Nadu, Gujarat, Maharashtra and Andhra Pradesh.

Sachin Omkar Kadam, a grape farmer from Mohadi village in Nashik district, Maharashtra, has been using a drip irrigation system for 19 years. All the farms in his village use drip irrigation. “Here, farmers using flood irrigation can only farm for half a year. A drip farmer can farm all year round,” he said. Micro irrigation has been promoted by the central and state governments through subsidies. Although over the years, Kadam has mostly invested in micro irrigation from his own pocket, in recent years, he received a state subsidy which covered half the cost of a new drip system.

Nonprofits, research institutes and farmer-producer companies have also been popularising micro irrigation techniques for years. International Water Management Institute (IWMI) has been involved in promoting and demonstrating micro irrigation systems across India. Recently, between 2020 and 2023, the institute extended its work to Odisha and Assam. “The demonstration aimed to create awareness among farmers about the benefits of micro irrigation, such as water savings and improved crop yields. After conducting training sessions and meetings with farmers, around 30 farmers applied for government subsidies to adopt these systems,” said Smaranika Mahapatra, a researcher at IWMI who specialises in agricultural water management.

What are the different types of micro irrigation?

There are broadly three types of micro irrigation systems currently used — sprinkler (or spray), drip (surface and subsurface) and bubbler.

In sprinkler or spray irrigation, pressurised water is sprayed over plants. This is a widely used method globally. In surface drip irrigation, water is released in a field through pipes placed on the ground. These tubes have holes called emitters that release the water drop by drop. In subsurface drip irrigation, pipes are buried below the soil to release water. This ensures water reaches the root zone of the plant directly with the least amount of evaporation. In both surface and subsurface drip, the rate at which water is applied is slower than sprinklers but water is applied more frequently. In bubbler irrigation, water is applied through a small stream or fountain to the soil’s surface.

The most popular micro irrigation methods in India are drip and sprinkler systems.

“Micro irrigation systems can be selected and designed for different types of crops based on crop spacing, water requirements, and growth patterns,” said Tiwari. “For widely spaced crops like orchards, vineyards, and row crops (such as oranges, mangoes, cotton), drip irrigation is more suitable. For closely spaced vegetable crops and crops that don’t follow a row pattern (such as. coriander, fenugreek, spinach), micro sprinklers or overhead sprinklers are better suited.”

What are the benefits of micro irrigation?

If a micro irrigation system is properly installed and operated, it can provide exactly the amount of water a crop needs in a controlled way. Experts claim that using micro irrigation can save 35 to 65 percent of water compared to the conventional method of flood irrigation.

Micro irrigation is a flexible system that can be used for different types of soils ranging from clayey to sandy. It can use water efficiently and distribute it evenly through a field. Since it needs less pumped water, it also uses less electricity. Micro irrigation also reduces evaporation which, in turn, reduces the wet area in a field. This reduces the growth of weeds, which saves the cost of herbicides and labour employed for weeding. Since drip irrigation does not wet the fruits and leaves of a plant, it also reduces plant diseases.

“Micro irrigation can also use mild saline water. It does not cause soil erosion and nutrient loss and can also be used in undulating terrain. It allows farmers to apply fertilisers directly to the root zone of a plant. It also reduces labour costs by automating water and nutrient application,” Tiwari told Mongabay India.

What are the drawbacks of micro irrigation?

During IWMI’s research on micro irrigation adoption in Odisha and Assam, Mahapatra found some issues that keep farmers from using drip and sprinklers. These include high upfront costs and lack of financial capacity among small farmers, lack of awareness about the technology, lack of consistent water and electricity sources in rural areas, small landholdings and farmers’ preferences for conventional irrigation methods.

Even if small farmers manage to install a drip or sprinkler system, they need to spend on post-installation maintenance and repair, which is not covered under government schemes. This could put additional financial pressure on farmers and make the system unsustainable.

Does India have any policies to promote micro irrigation?

India has been promoting micro irrigation as a water-saving technique on its farms. The government launched Pradhan Mantri Krishi Sinchayee Yojana (PMKSY), an umbrella scheme in 2015-16, jointly run by three Ministries – Jal Shakti, Agriculture and Farmers’ Welfare and Rural Development. One of the goals of the scheme is to improve water efficiency and reduce water wastage in farms. This centrally sponsored scheme provides farmers subsidies for installing micro irrigation systems.

The scheme has a Per Drop More Crop (PDMC) component which promotes drip and sprinkler irrigation systems through awareness programmes and technical support apart from subsidies. Over 8 million hectares of land in India have been covered under micro irrigation through PDMC in the last nine years, according to a written reply given by Arjun Munda, the Union Minister of Agriculture and Farmers’ Welfare in Lok Sabha this year.

India also created the Micro Irrigation Fund (MIF) with the National Bank for Agriculture and Rural Development (NABARD) in 2018-19, with an initial amount of 5,000 crore rupees, which was available until 2023. States could take loans from the MIF to start projects to expand and incentivise micro irrigation beyond the PDMC scheme. By the end of 2022, NABARD sanctioned 14 projects under micro irrigation in Andhra Pradesh, Gujarat, Haryana, Punjab, Rajasthan, Tamil Nadu, Uttarakhand and West Bengal.

State governments also provide further subsidies to make this technology more accessible for farmers. “Micro irrigation adoption rates vary across India due to factors like water availability, crop patterns and government programmes and policies. Despite these policies, the adoption rate has been relatively low due to factors like high initial costs even after subsidies, lack of technical knowledge among farmers, land fragmentation and behavioural barriers. These challenges should be addressed through more farmer training programmes, easier financing options, and promoting successful case studies of farmers adopting micro irrigation profitably,” said Mahapatra.

Does micro irrigation truly save water?

“Micro irrigation saves water at the farm scale, but the same amount of water savings may not be realised at the aquifer or river basin scale,” said Sachin Tiwale, a fellow at the Ashoka Trust for Research in Ecology & the Environment (ATREE), who specialises in water governance. According to him, micro irrigation is promoted with the objective that after the installation of a subsidised system, water consumption will reduce and used more efficiently and the water saved in farms will be directed to other users such as deprived farmers, growing urban areas or industries. He also added that the PDMC component of PMKSY in dark zones (areas where aquifers are overexploited) is based on the underlying assumption that after switching to micro irrigation, the overexploitation of aquifers will be minimised apart from reducing water use.

However, a 2014 study on the impact of micro irrigation by the Ministry of Agriculture showed that farmers who used micro irrigation increased the irrigated area from the same water source. “Farmers using micro irrigation tend to increase the irrigated area, sow more crop cycles in a year or sow water-intensive crops which bring more money. This means they end up using the same amount of water they were using for flood irrigation,” he said. He also explained that flood irrigation allows part of the water to percolate underground, which recharges aquifers and aids base flow and ultimately moves to streams and rivers. This water either becomes available to nature or to other farmers downstream. “When we shift a farm from flood to micro irrigation, the percolation stops. Large-scale micro irrigation affects the hydrology of a region.”

Tiwale recommended a mechanism for regulating water use and controlling water allocation to ensure that the water saved through micro irrigation goes to another user, which is not happening currently. He also emphasised that regulation becomes even more important in the dark zones because farmers using drip and sprinklers may keep on pumping groundwater if no one monitors their water extraction from aquifers.

Tiwale shares, “Our national water policy emphasises that water should be planned, managed, and accounted for at the basin or sub-basin scale. If you don’t have regulation in place, micro irrigation may not necessarily save water on the river basin scale.”

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Banner image: Sprinkler systems are a widely used micro irrigation method across the world. Image via Pixabay.

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Aditi Tandon Senior Production Editor

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