14. Extent and Scope for the Adoption of Water Saving Technologies: An Analysis of Drip and Sprinkler Irrigation in India

Monetary values used in this chapter are in Indian Rupees (INR) represent value in current prices, unless otherwise specified.

Although individual farmers adopting drip and sprinkler method of irrigation in different crops are able to realise considerable saving of water through increased irrigation efficiency (IE), Grafton et al. (2018) argue that the higher efficiency rarely reduces water consumption, which they call it as “the paradox of irrigation efficiency”. They argue that “…… . water saved at a farm scale typically does not reduce water consumption at a watershed or basin scale. Increases in IE for field crops are rarely associated with increased water availability at a large scale”. As per their arguments, water losses to farmers and irrigation system do not disappear and they typically recovered and reused elsewhere in a watershed or basin. Citing examples from different countries, Grafton et al. (2018) are trying to strengthen their arguments. For instance, they mention that Snake River, Idaho, where farmers have increased their IE, but this has reduced groundwater recharge and led to decline in the Eastern Snake Plain aquifer by about 30% since the mid-1970s despite increased precipitation. Similarly, the Souss and Tensift Basins of Morocco, where the increased adoption of drip irrigation with the support of subsidies, reduced recoverable return flows, principally to overexploited aquifers. This intervention led to increased water consumption and also exacerbated groundwater over-exploitation in Morocco due to crop intensification. Although these arguments seem to be theoretically sound, one cannot always say that increased IE will not guarantee any reduction in water consumption in a basin which is determined by various factors. There is every possibility that a large-scale adoption of micro-irrigation (drip and sprinkler) in any given region is expected to save water as well as reduce the gross consumption of water, both of which are expected to reduce the exploitation of groundwater and increase water availability in a basin. Going by the arguments of Grafton et al., any effort taken to increase IE in a region will not reduce water consumption. Does this mean that the investment made on improving water use efficiency in a basin by any form including drip and sprinkler method is wasteful expenditures? In any case, given the imperfect information about the level of return flow that can occur in a given basin, well structured scientific water accounting studies need to be conducted in different basins to firm our understanding about the paradox of irrigation efficiency. I am thankful to one of the referees (Board Member) of the book proposal for suggesting me to look into the issue of paradox of irrigation efficiency in the context of drip method of irrigation, which helped me to think more on this issue.

The results of experiments carried out in different locations in India on various crops are available in INCID (1994, 1998) and Narayanamoorthy (2005).

One of the major benefits of adopting drip method of irrigation is saving in electrical energy used for operating pumpsets to lift water from wells. This benefit has not been estimated and highlighted by many studies that were carried out using field survey data. Narayanamoorthy (1996) is probably the first Indian economist who made effort to estimate the saving of electricity in drip irrigated crops using field survey data. More details on the impact of drip method of irrigation on electricity use on different crops can be seen from Narayanamoorthy (2005).

One of the serious constraints faced by the researchers working on micro-irrigation is the data availability. Though most of the area currently cultivated under micro-irrigation is established through various government sponsored schemes, coverage of area under MI by states and by crops are seldom published by any single agency. This does not allow the researchers to study the trends and determinants of micro-irrigation across states in detail. This section is written with great data constraint.

NCPA was later renamed as the National Committee on Plasticulture Applications in Horticulture (NCPAH) due to the prominent role plasticulture plays in the productivity of horticultural crops.

A number of factors are responsible for the rapid development of drip irrigation in Maharashtra. First, state government has been very keen in promoting drip irrigation on a large scale by providing subsidy, technical and extension services to the farmers. Maharashtra government has been providing subsidy since 1986–87 onwards through state sponsored schemes. Second, the area under irrigation from both surface and groundwater is quite low and hence, many farmers have adopted drip method of irrigation to avoid water scarcity largely in divisions like Nashik, Pune, etc. Third, owing to continuous depletion of groundwater, farmers were not able to cultivate wide spaced and more lucrative crops like grapes, banana, pomegranate, orange, mango, etc., by using surface method of irrigation in many regions. Farmers had no choice except adopting drip irrigation as these crops are most suitable for drip method of irrigation. Importantly, farmers who have adopted drip irrigation initially for certain crops have realised the benefits of such method of irrigation in increasing the water saving and productivity of crops. All these factors have induced many farmers to adopt drip method in some of the regions in Maharashtra.

Benefit-cost ratio (BCR) estimated using properly designed methodology with field survey data reveals that DMI is economically viable even for small and marginal farmers cultivating different crops in Maharashtra and Tamil Nadu. The estimated BCR varied from 2.30 to 2.36 in crops like banana and sugarcane, from 2.79 to 3.91 in vegetable crops like brinjal and chilli and from 1.79 to 1.98 in the case of cotton crop even without availing subsidy. The results of these studies also suggest that farmers will be able to payback the entire capital from the profit of the very first year itself. More details about the estimate on BCR can be seen from Narayanamoorthy (1997, 2018) and Narayanamoorthy et al. (2018).

This estimate also matches with the country level estimate earlier made by Narayanamoorthy (2004).