Potassium Nutrition of Forage Grasses

This chapter discusses some factors of potassium (K) availability in relation to forage grasses, identifies the conditions favorable for obtaining K responses from forage grasses, and presents yield and quality responses of forage grasses to K applications. Forage grasses are produced for consumption by ruminant animals and may be harvested by grazing or harvested mechanically. Different sources of commercial fertilizers have generally been equally effective for forage grasses. Potassium fertilization of K-deficient plants improves performance and vigor of forage crops. Potassium levels in temperate forage grasses have been consistently associated with the incidence of grass tetany or hypomagnesemia in ruminant animals. Management of grasses should be designed to provide adequate K for the intended level of production but without greatly exceeding the K requirement of the grass. Monitoring soil and plant nutrient levels will then allow agronomists to prescribe nutrient applications that will provide sustained production of high-yielding, high-quality forage grasses.