Irrigating crops is an agricultural practice that goes back thousands of years in human history. Despite significant advances in technology over time, the basic purpose of irrgation is much the same: to supplement water available through rainfall for the purpose of increasing crop yields and/or crop quality. But supplying water to forage production must carefully consider several factors to be worthwhile. Each forage species has specific qualities and each will respond differently to irrigation and other modifications. The costs of irrigation must be weighed against the potential gain in yield or improved quality. So markets must be evaluated. Growers must ask: how much water is needed as a supplement, how easily can the water be distributed, when and how should the water be dispersed, and do I have the equipment and/or to do so?

In the more arid parts of the U.S., profitable forage production would be difficult, if not impossible without irrigation. For example, in much of the arid to semi-arid west, rainfall is often less than 18 inches (45.7 centimeters) a year. Furthermore, droughty periods occur almost every year, and without supplemental water even established forage stands may yield very poorly.

Around 618 million acres (250 million hectares) are irrigated around the world. That land is only a portion of all cultivated land but very significant. Most of the irrigation occurs in a handful of countries because it is expensive but is increasing as a whole. Irrigation is bound to part of the solution to feeding the growing world population.

Irrigation is used to supply a plant with water so that the plant may flourish and that means both in amount and quality.