Irrigated crops produce about 40% of total agricultural output; their yields are typically twice those of rain-fed crops. For instance, the Food and Agriculture Organization (FAO) estimated that irrigated cereals produce yearly about 60% of a total of 1.2Gt in the developing countries [3]; globally-averaged irrigated cereal yields for developing countries are thus 3.9tons/ha, compared with roughly 1.8tons/ha under rain-fed conditions