Use of Poor-quality Water for Agricultural Production

Freshwater resources are being squeezed all over the world because of shifts in climate patterns, and a severe shortage of water is the major threat to food security. Most developing countries are overpopulated, and the quality and quantity of food available for these ever-increasing populations are questionable. Wise distribution of freshwater among different stakeholders is a prerequisite, giving priority to domestic use. For agriculture, wastewater of a suitable quality should be used with proper treatment and good management practices. A huge volume of wastewater is being generated, which must be properly managed for use in growing different crops. Similarly, farmers use groundwater as a supplementary source of surface water for irrigation. Unfortunately, most groundwater is brackish because of high salinity and/or sodicity. In this chapter, alternative sources of irrigation water are identified and their compositions are addressed comprehensively. It has been indicated that most alternative water sources are of low quality, and their use in agriculture demands continuous management and monitoring. Different available options are focused on, especially those acceptable to farmers, because resource-poor farmers are mostly concerned with economics. These management choices include alternative irrigation with canal water, conjunctive use of wastewater with good or marginal water, use of different organic and inorganic amendments, etc. Case studies have evaluated economic use of poor-quality water with canal irrigation. This chapter provides insights into opportunities and challenges for effective use of poor-quality water in agriculture.