Sustainable Water Systems for Agriculture and 21stCentury Challenges

Availability and pollution of freshwater water supplies will be the dominant issues for the global society in the 21st century. With increasing population and climate change scenarios, the demand for water will continue to increase for agriculture, especially irrigation, and other economic uses to meet food, fiber and energy-security needs of the society. At the same time, there is good likelihood that the availability of freshwater will decrease with the fast melting of world's major glaciers. In addition, the water quality of rivers, lakes, oceans, and aquifers will further degrade from the discharge of domestic, municipal, industrial, and agricultural water. Currently, more than five million people die every year because of water-borne diseases and 1.5 billion get sick every year because of poor sanitation or use of poor quality drinking water. Therefore, water-resource management will continue to be of great importance, and global society needs to develop strategies on developing efficient methods for water use and management/reuse of poor quality water for agriculture. The objective of this chapter paper is to highlight some of the water challenges of the 21st century and identify some of the innovative water management strategies and agricultural practices that can be used in agricultural watersheds to improve water quality and water availability for all needs of society. This chapter also discusses issues related to global warming, melting of glaciers, rise of sea levels, and how these issues will affect water sustainability and food security issues of the 21st century.