Today is World Water Day 2013, celebrating the International Year of water cooperation. A paradigm of the world’s water challenges is that although agriculture accounts for approximately 70% of global water resources, around one billion people are chronically hungry.

As water for irrigation and food production constitutes one of the greatest threats to the sustainability of the world’s freshwater resources, we discuss four methods of reducing water use in agriculture, methods that can reduce water use without limiting, and sometimes increasing, food production.

Grow crops that use less water. This can mean either crops that due to their physiology require less water. For example growing grapes and olives requires significantly less water than tomatoes or bananas. Or it can mean crops bred to require less water such as the Water Efficient Maize for Africa (WEMA) project.  Of course the choice of crops grown is also dependent on environmental…