Projections made by the International Water Management Institute (IWMI) indicate that one-third of the world population would face absolute water scarcity by the year 2025. NITI Aayog’s report (2018) on ‘composite water management index’ also underlined the depressing state of water stress.

 

Though India has the largest irrigated area in the world, about 85 per cent of total irrigation potential (139.90 million hectares) has already been created, leaving limited potential for future use. An estimate of the Ministry of Water Resources (2008) shows the total demand for water will overshoot the supply by 2050. With this alarming scenario, how are we going to solve the ever increasing water scarcity problem?

 

There’s much scope for easing water scarcity in agriculture. The agricultural sector (irrigation) currently consumes about 80 per cent of water in India, thanks to the inefficient conventional flood method of irrigation (FMI). Data on water use efficiency indicates that India uses 2-3 times more water than major agricultural countries like China, Brazil and the US to produce one unit of food crop.

 

Benefits of drip irrigation

Drip method of irrigation (DMI) has been found to increase water-use efficiency by saving a substantial amount of water. What is DMI? Unlike FMI, the drip method supplies water directly to the root zone of a crop through a network of pipes and emitters. Since it supplies water directly to the crop, rather than the land around, water losses occurring through evaporation and distribution are significantly reduced. The on-farm efficiency of the drip irrigation system is estimated to be over 90 per cent; it is only 35-40 per cent for FMI.

 

DMI was introduced in India during the mid-1980s primarily to save water. But it generates a lot of other benefits as well. That there is water saving of 30-70 per cent for different crops under DMI when compared to FMI has been well established. While reducing the cost of cultivation substantially, especially in irrigation, weeding and inter-culture, DMI also helps increase the productivity of different crops by 30-90 per cent.

 

Reduced water consumption also curtails the use of electricity for operating pumpsets. With better productivity and quality of crops cultivated under DMI, farmers are able to realise substantially higher income. A nationwide study conducted to find out the impact of National Mission on Micro Irrigation (NMMI) during 2014 covering 13 States reveals that DMI has benefited farmers significantly. While increasing productivity by 42-53 per cent in fruit and vegetable crops, DMI helps reduce irrigation cost by 20-50 per cent, electricity consumption by around 30 per cent and fertiliser consumption by about 28 per cent.

 

One of the major questions often asked is whether the fixed investment required for installing a drip system is economically viable. But the cost-benefit analyses done using field survey data reveal that DMI is economically viable even for small and marginal farmers cultivating different crops. Realising the significance of DMI, various promotional programmes have been introduced to increase its adoption by the Central and State governments since the early 1990s. Maharashtra is probably the first State to have taken a number of initiatives — subsidy programme being one such — to popularise DMI even during the mid-1980s.

 

To achieve the objective of ‘per drop more crop’, the Central government is taking a series of efforts to increase its adoption. While Centrally-sponsored schemes have been in vogue since the early 1990s, the National Mission on Micro-Irrigation (NMMI) introduced during 2010-11 and the Pradhan Mantri Krishi Sinchayee Yojana (PMKSY) launched in 2015 have significantly increased DMI adoption. As a result, the area under DMI has risen from a mere 1,500 ha in 1985-86 and 70,859 ha in 1991-92 to 4.24 million hectares as on March 2017.

 

India has enormous potential for DMI, which should be harnessed to reduce water scarcity. The Indian National Committee on Irrigation and Drainage, in its report on Drip Irrigation in India, indicates that about 80 crops can be grown viably under DMI. Although DMI is considered to be highly suitable for wide spaced and high-value commercial crops, it is also being used for cultivating oilseeds, pulses, cotton and even paddy and wheat. The area under DMI has risen sharply in recent years but it is still far lower than the potential.

 

The agenda ahead

The Task Force on Micro-Irrigation in India (2004) estimated India’s total drip irrigation potential at 27 million hectares as. In spite of having many advantages, the area under drip-irrigation accounts for a mere 4 per cent of gross irrigated area and about 15 per cent of its total potential as of 2016-17. The adoption of DMI is also concentrated only in a few States. With the current pace of adoption, it may take a long time to achieve full potential. Given the looming water scarcity and variations in rainfall pattern due to climate change, more efforts are needed to increase the pace of DMI coverage.

 

First of all, the capital cost required for DMI should be brought down substantially. A special subsidy programme may be introduced for water-intensive crops like sugarcane, banana and vegetables. A differential subsidy scheme for water-scarce and water-abundant areas should be introduced. Subsidy is provided to a maximum of five hectares per beneficiary under NMMI, which should be done away with.

 

All the areas of sugarcane cultivated using groundwater should be brought under DMI within the next 10-15 years. For encouraging the adoption of drip irrigation, a special scheme may be introduced linking bank loan facility for digging wells with electricity connection for pumpsets to those farmers who are ready to adopt drip irrigation.

 

Currently, water from surface sources (dams, reservoirs, etc) is not used for DMI. At least 10 per cent of water from each irrigation project should be allocated only for DMI. Appropriate pricing of canal water and electricity will also help in increasing the area under DMI.