February 2008

With drought, declining water tables, or legal restrictions, some irrigated acres won't receive enough water this summer to grow a good grain or root crop.

Forage crops also need water for high production, but unlike most annual crops, at least some useful yield can be gathered when total water is very low. If you expect limited water availability to continue for several years, a perennial forage would eliminate the cost and time of establishing a new crop each year.

Switchgrass is a good option because it is less expensive to plant, its primary water needs occur in early summer when water is available, and it can be managed successfully for hay or pasture. Other good warm-season grass options include indiangrass and big or sand bluestem. Some of the wheatgrasses and bromegrasses as well as alfalfa can work with limited irrigation, but these cool-season plants respond best to water applied during spring. For some irrigators, water won't become available until later in the season.

Of course, annual forages like pearl and foxtail millet, cane, and sorghum-sudangrass are relatively water efficient and will yield proportionately to the amount of water they receive. Grains like rye, triticale, and oats can be used for fall and spring forage if you have moisture at those times.

Bruce Anderson
Extension Forage Specialist