Irrigation is a land-conserving technology. It gives higher yields by reducing losses attributable to the vagaries of the weather, encourages the use of complementary inputs such as fertilizers aI)d improved seed varieties, and improves the prospects for multiple cropping. Irrigation also is a land-creating technology in that it opens up arid and semiarid areas to high-yielding agriculture. Consequently, it might be expected to become increasingly important as agricultural expansion presses upon the limits of a nation's land resources.