IRRIGATION

In irrigated agriculture, water taken up by crops is partly or totally provided through human intervention. Irrigation water is withdrawn from a water source (river, lake, aquifer or reservoir) and applied to the farm through an appropriate conveyance infrastructure. To satisfy their water requirements, irrigated crops benefit from both more or less unreliable natural rainfall, and from irrigation water. Irrigation provides a powerful management tool against the vagaries of rainfall and makes it economically attractive to grow high-yield seed varieties and to apply adequate plant nutrition as well as pest control and other inputs, thus giving room for a boost in yields. Figure 3 illustrates the typical yield response of a cereal crop to water availability and the synergy between irrigation, crop variety and inputs. Irrigation is crucial to the world's food supplies. In 1998, irrigated land made up about one-fifth of the total arable area in developing countries but produced two-fifths..

Primary location: Nairobi Kenya