ABSTRACT
Alfalfa (Medicago sativa) is a legume widely grown as feed for livestock, especially for dairy cows during milk production. It may be pastured, fed green as whole herbage or chopped, ensiled, or fed dry as loose hay, chopped hay, or in bales. The herbage also is dehydrated to be used in mixed rations of rabbits, poultry, swine, and horses, or as a leaf meal. Alfalfa grows best where winters are mild and summers are warm. In the upper latitudes "where subfreezing temperatures prevail during winter, cold-hardy types have been developed. About 11 million ha of alfalfa are being harvested for hay and silage in the USA, and an additional undetermined crop area is pasture. As farmers obtain higher yields and as the plant breeders release higher-yielding, persistent, pest-resistant cultivars, it will he necessary to increase fertilization, especially of ? and K, if the stand is to survive and remain highly productive.
