FARM LEVEL WATER FOOTPRINTS OF CROP PRODUCTION: CONCEPT AND ACCOUNTING

Abstract

The water resources potential ofIndia which occurs as natural runoff in the rivers are estimated at about 186.9 M ha-m. Considering both uneven distribution of water resource over space and time about 112.2 Mha-m of the total potential can be put to beneficial use, 69 M ha-m through surface water resources and 43.2 M ha-m by groundwater (Kumar and Kar, 2013). India experiences high degree of spatial variability of annual rainfall, highest annual rainfall of 11,690 mm is recorded at Mousinram near Cherrapunji, Meghalaya, and lowest of 150 mm at Jaisalmer of Rajasthan. Average 75% precipitation of the country occurs during southwest monsoon season (June to September) only (Kumar and Kar, 2013). The country's vast cultivated area (82 M ha) is still rainfed. For adequate living standards as in western and industrialized countries, a renewable water supply of at least 2000 m3 per person per year is necessary. If only 1000-2000 m3 per person per year is available, the country is 'water stressed', while the value comes below 500 m3 per person per year, the country is called 'water scarce' (Kumar and Kar, 2013). With rapid population growth and rising expectation of better life, there will be ever increasing demand of water for various competing sectors like domestic, industrial and agricultural needs. Also more and more water will be required for environmental concerns such as aquatic life, wildlife refuges and recreation. With changing global climatic patterns coupled with declining per capita availability of surface and ground water resources, sustainable water management in agriculture is a great challenge in India. With increasing water demand from other sectors, agricultural water use in India will face stiff competition for scarce water resource in future. Therefore, the available utilizable water resources would be inadequate to meet the future water needs of all sectors unless the utilizable quantity is increased by all possible means and water is used efficiently. Adoption of suitable agro-techniques for crop cultivation is need of the hour to produce more crops with less water so as to check the decline of surface and ground water resources in India. Recognizing the importance of the above fact, the country has developed water saving irrigation technologies like resource conservation technology including laser· leveling, improved irrigation methods including drip and sprinkler, rainwater harvesting and grQundwater recharge techniques, diversification with low duty crops, waste water management, conjunctive and multiple use of water etc. to achieve 'more productivity per drop'. But now the priority is the development of the indices those indicate appropriation of freshwater resources from a particular management system. In this regards water footprints which is the "ratio of the volume of consumptive water use to the quantity of produce of interest" can be used to indicate direct and indirect appropriation of freshwater resources (Hoekstra, 2003; Hoekstra and Chapagain, 2008). The term "freshwater appropriation" includes both consumptive water use (the green and blue water footprint) and the water required to assimilate pollution (the grey water footprint), (Postel etal., 1996 and Chapagain etal., 2006).