This publication addresses improving water productivity to relieve problems of scarcity and competition to provide for food and environmental security. Draws from scientists having a multitude of disciplines to approach this important problem In a large number of developing countries, policy makers and researchers are increasingly aware of the conflicting demands on water, and look at agriculture to be more effective in its use of water. Focusing on both irrigated and rain-fed agriculture, this book gives a state of the art review of the limits and opportunities for improving water productivity in crop production. It demonstrates how efficiency of water use can be enhanced to maximize yields. The book represents the first in a new series of volumes resulting from the Comprehensive Assessment of Water Management in Agriculture, a research program conducted by the CGIAR's Future Harvest Centres, the Food and Agriculture Organization of the United Nations and partners worldwide. It will be of significant interest to those working in areas of soil and crop science, water management, irrigation, and development studies.