Irrigated alfalfa is one of Montana's premier cash crops.
Though irrigated alfalfa hay production averages 3.3 tons per acre statewide, many producers routinely harvest 5 to 7 tons per acre with high management. A major consideration for optimum alfalfa tonnage and quality is the timeliness and amount of irrigation applied. Insufficient or poorly-timed irrigation reduces productivity. On the other hand, over-irrigation is inefficient, and can cause loss of nutrients, soil and the stand itself. Due to a late fall in 1998 and dry spring conditions, many alfalfa fields began the 1999 season with a subsoil moisture deficit, and irrigation during July 1999 was intensive.