Improving agricultural water productivity: A necessary response to water scarcity and climate change in dry areas

Abstract

Water resources in the dry areas are limited. Most of the available water is tapped and only limited new water is expected from non-conventional sources. As more water will be needed for other priority sectors, less water will be available for agriculture. This decline comes to challenge the attempts to increase food production and to enhance food security. Climate change adds to this challenge in the dry areas as precipitation is expected to decline and drought to intensify. Agriculture as a result must cope with the increasing demand for food, feed, and fiber, but with less water. It is, therefore, essential that substantial changes be made in the way water is valued and managed to help overcome water shortages. The logical response is to produce more with less water; that is to improve water productivity (WP) which is the return for a unit of water consumed or depleted. WP in the dry areas is generally low and there is a great potential for its improvement. There are three primary ways to enhance agricultural WP: (a) Reduce non productive water depletion; (b) Improve plant, animal, etc. productivity per unit of water beneficially consumed; and (c) Allocate water to the more water productive options. Substantial and sustainable improvements in agricultural water productivity can only be achieved through integrated management at all scales. On-farm water-productive techniques include deficit irrigation, supplemental irrigation, water harvesting and precision irrigation. Improved techniques if coupled with improved irrigation management, better crop selection and appropriate cultural practices, improved genetic make-up, and timely socioeconomic interventions will help to achieve this objective. Conventional water management guidelines should be revised to ensure maximum water productivity instead of land productivity. Policy reforms and empowered new institutional setups can ensure sustainable improvement in water use in agriculture.