Given the need to increase productivity while saving water, advanced methods of irrigation will play a key role in the future of Indian agriculture. As per the Economic Survey 2018-19, states such as Tamil Nadu, Karnataka, Maharashtra and Andhra Pradesh (high-water-consuming sugarcane and paddy producers) that have high land productivity tend to have very low irrigation water productivity. This reflects the inefficient use of water and the need to recalibrate cropping patterns. Also, predominant use of the flood irrigation method leads to low water use efficiency (35-40 per cent) because of high distribution losses. Hence, it is critical to adopt improved methods of irrigation and irrigation technologies to increase water productivity.
Micro-irrigation: Increasing slowly but steadily
Micro-irrigation has slowly started gaining prominence over conventional flooding methods of irrigation and is gradually emerging as a demand-driven technology. Since 2014-15, the area covered under micro-irrigation systems has grown at a compound annual growth rate of about 18.2 per cent to reach 1.08 million hectares in 2019-20. State-wise, the maximum area was brought under micro-irrigation in Tamil Nadu (23.8 per cent), followed by Karnataka (23.27 per cent) and Andhra Pradesh (11.34 per cent).
In terms of achieving physical targets, the area covered under micro-irrigation in 2015-16, 2016-17 and 2018-19 surpassed the set targets, whereas there was 85 per cent achievement during 2019-20. In terms of achieving financial targets, there was more than 100 per cent utilisation from 2014-15 till 2016-17, and 70-80 per cent utilisation in 2017-18 and 2018-19. During 2019-20, the achievement rate stood at 87.02 per cent.
Types of micro-irrigation
There are two main types of micro-irrigation – drip irrigation and sprinkler irrigation. Drip irrigation involves dripping water on to the soil at very low rates via a system of small diameter plastic pipes fitted with outlets called emitters or drippers. Water is applied close to the plants so that only that part of the soil in which the roots grow is wetted. During 2019-20, an area of 0.54 million hectares was brought under drip irrigation, as against the target of 0.71 million hectares, an achievement of 76.2 per cent. State-wise, Tamil Nadu has the highest rate of drip adoption (2019-20).
In the sprinkler irrigation method, water is distributed through a system of pipes usually by pumping. It is then sprayed into the air through sprinklers so that it breaks up into small water drops that fall to the ground. The area covered under sprinkler-type micro-irrigation systems increased from 37 per cent in 2015-16 to 48 per cent in 2019-20, leading to a decrease in drip-type systems (from 63 per cent to 52 per cent during the period under consideration). State-wise, Karnataka has the highest adoption rate of sprinkler systems (2019-20). Though less efficient than drip irrigation, the greater deployment of sprinkler irrigation can be attributed to the ease of laying pipes over undulating lands.
Government push to micro-irrigation
While there have been some policy initiatives in the past, the real thrust to micro-irrigation came in 2006 when the government launched a centrally sponsored scheme. This was later upgraded to the National Mission on Micro Irrigation (NMMI) and was implemented till 2013-14. During 2014-15, the NMMI was subsumed under the National Mission for Sustainable Agriculture and was implemented under the On-Farm Water Management component of the scheme. The PradhanMantriKrishiSinchayeeYojna (PMKSY), launched in 2015-16, integrated micro-irrigation with the Per Drop More Crop (PDMC) component. During 2019-20 (as on February 25, 2020), 4.31 million hectares was brought under micro-irrigation under the PDMC component.
Technology uptake: Increase in penetration
Technology in the irrigation sector has evolved significantly over the past decade. The best practices and technology for water management refer to the application of the optimum water quantity, scheduled at the right time with highest water application efficiency.
Canal network flow monitoring system (CNFMS)
CNFMS is a comprehensive system used to monitor canal systems and on-farm parameters using sensors, remote terminal units and information and communication technology. The system generates information on daily water availability, water flow and release, on-farm parameters at designated points, weather parameters from an established system, etc. The Water and Land Management Training and Research Institute, Telangana, has deployed CNFMS as a part of its ClimaAdapt Project.
Irrigation scheduling, an essential management practice for a farmer, is about planning when to irrigate and how much water to apply in order to maintain healthy plant growth during the crop season. Proper timing of irrigation water applications is crucial to meet the water needs of the crop to prevent yield loss due to water stress, maximise irrigation water use efficiency and minimise the leaching potential of pesticides that could impact groundwater quality.
Precision farming is project-level application of micro-irrigation and fertigation and is about doing the right thing at the right time and at the right place. It is a modern agricultural practice that involves the use of technologies such as remote sensing, Global Positioning Systems and Geographic Information Systems for improving productivity and profitability. One of the key objectives of the PMKSY-PDMC component is increasing the productivity of crops and income of farmers through precision water management.
Several agri-tech start ups have devised systems like automated drip and sprinkler irrigation systems supported by soil moisture sensors and a micro controller. The sensors measure the water availability at different depths in the soil and transmit the information to computers and mobile devices. Rain guns are used to spread water like rain, particularly for sugarcane and maize crops.
Meanwhile, an Israel-based irrigation technology developer, Netafim, has been selected for the construction of four large community irrigation projects, connecting almost 60,000 farmers in over 100 towns to advanced agricultural technology and providing water to 54,000 hectares of land. The project, worth over $100 million, will improve infrastructure in agricultural communities in the southern states of Karnataka and Andhra Pradesh. In Singataluru, Karnataka, Netafim will manage two projects covering 41 villages, assisting approximately 15,000 farmers. The Ananthapuramu project in Andhra Pradesh will cover 22 villages and 13,000 farmers, and the Tarikere project in Karnataka will benefit 45 villages, home to approximately 27,000 farmers.
The way ahead
Despite some promising initiatives, current irrigation practices are far from satisfactory. They are characterised by poor water use efficiency, suboptimal utilisation of the irrigation potential, low coverage of advanced micro-irrigation systems, overexploitation of groundwater sources, widespread growing of water-intensive crops and poor freshwater management. The Task Force on Micro Irrigation (2004) estimated a total potential of 69.5 million hectares based on the area under crops that are suitable for micro-irrigation. This includes 27 million hectares for drip irrigation and 42.5 million hectares for sprinkler irrigation. Currently, the total area covered under micro-irrigation is only about 15 per cent of the total crop-wise potential.
However, the situation is slowly changing with increased interest from the government and the private sector in efficient and smart management of freshwater resources for irrigation purposes. In May 2018, the Cabinet Committee on Economic Affairs approved an initial corpus of Rs 50 billion for setting up a dedicated Micro Irrigation Fund (MIF) under the National Bank for Agriculture and Rural Development for the PMKSY. With the operation of the MIF, it is expected that states that are lagging behind in the adoption of micro-irrigation will also be encouraged to take advantage of the fund for incentivising farmers, as is being done by the better performing states.
Meanwhile, integration of traditional methods and modern-day technologies is also required to align technologies to local requirements. For instance, some of the traditional irrigation techniques such as johads in Haryana, aharpyne in Bihar, apatani in Arunachal Pradesh, phad in Maharashtra, kuhl in the Himalayan region and bamboo drip irrigation in Meghalaya have helped to achieve better water use efficiency.
There also exists significant potential for public-private partnerships (PPPs) in irrigation. The government’s target of covering around 0.5 million hectares per annum under micro-irrigation with a budget of Rs 10 billion in the PMKSY is far below the country’s overall micro-irrigation potential, leaving a lot of scope for future development. It is therefore essential to take up integrated micro-irrigation projects, which implies implementation of community-based micro-irrigation projects on scalable PPP models.