Better crop planning based on local weather conditions is the fundamental approach to wise water management.
Sumit Roy & Murli Dhar
Marathwada is one of the most water-deprived regions of Maharashtra. In recent times, it is facing one of the biggest water crises. The impact is felt on all sectors and users of water—agriculture, domestic and industry. If one were to dig a bit deep into the causes of the enormous crisis the region is facing now, one would see that it is a combination of natural factors such as poor rainfall coupled with faulty environmental planning based on a myopic approach towards the actual scenario. The crisis is aggravated by poor water planning especially when it comes to choice of crops, which has an ultimate impact on the use of water for irrigation.
Therefore, it becomes essential to review the water crisis from wide range of perspectives—natural manifesting as changes in climate, inefficient usage of water, overall planning and budgeting of water resources in a region. The entire Marathwada region receives an average annual rainfall of 700-800 mm. It is expected that crops with less water requirement would dominate the region, but in practice, sugarcane, cotton and soybean are found to be predominant.
Traditionally, Marathwada grew millets, oil seeds which have now been taken over largely by water-intensive cash crops. From 1990 to 2013, there has been a significant decrease in area under sorghum (from 63 lakh ha to 30 lakh ha), pearl millets (from 19.40 lakh ha to 7.62 lakh ha), oilseed crops like groundnut (from 8.64 lakh ha to 3.15 lakh ha) and safflower (from 6.34 lakh ha to 1.07 lakh ha). These have been taken over by crops like sugarcane (increase in area from 5.36 lakh ha to 10.99 lakh ha), cotton (from 27.21 lakh ha to 41.60 lakh ha) and horticulture crops.
The former require more water than the latter. The water requirement of sorghum, pearl millet, ground nut and safflower are 500–550 mm, 350–400 mm, 400–450 mm and 200–300 mm, respectively. The water requirement of these crops, referred as rainfed crops, is within the average annual rainfall of the region and any shortage of downpour might not affect the water availability in the aquifer. In contrast, the water requirement of crops like sugarcane, cotton and horticulture crops like sweet lime is 2,000–2,200 mm, 600–700 mm and 900–1200 mm respectively.
Instead of prescribing water efficient crop planning, the current policy aims to mitigate water crisis mainly by promoting drip irrigation in water intensive crops. In 2014, the Maharashtra government made drip irrigation mandatory for sugarcane cultivation. It is endorsed as the panacea to drought in the water scarce region. The total expenditure incurred by the state government on subsidies for drip irrigation between 2009 and 2014 works to Rs 1,918 crore and it may go up as high as Rs 4,000 crore, if 100% subsidy is provided.
While there is no doubt that drip irrigation is one of the most efficient irrigation systems, it fails to address fundamental issue regarding management of water resources through better crop planning. If one was to consider, Pareto’s law of optimality, then only enhancing crop production can’t make anyone better off without making at least one system worse off. The relative efficiency of drip irrigation system needs to be analysed with respect to this.
Water-saving technologies have been promoted widely as a practical means of improving the water-use efficiency and freeing up water for other uses. However, there is increasing evidence that, somewhat paradoxically, the technologies often contribute to intensification of water use by irrigated and rain-fed farming systems. This occurs when: (a) increased crop yields are coupled with increased consumptive water use and/or (b) improved efficiency, productivity and profitability encourages farmers to increase the area cropped and/or to adopt multiple cropping systems. In both the cases there are net water drafts from the hydrological system. From the grower’s perspective, water saving does not result in income gains for the farmers.
Given the fact that marginal cost of pumping groundwater for agricultural is negligible and canal water is not charged on volumetric basis, the opportunity cost of using water is almost nil. Also, promotion of conventional micro-irrigation systems may falter owing to absence of independent water sources and pressuring unit with most of the irrigators. Thus, there is a need to understand that better crop planning (based on local weather conditions) is the fundamental approach to wise water management. The task is not easy, as any decision to change the cropping sequence may affect the well-established sugar economy. However, desertification has a far greater cost.
Roy is associate director, while Dhar is director, Sustainable Agriculture Program, WWF-India