Relative Rates of Mineralization in Soil of Organic Nitrogen from Several Forage Crops1

Synopsis Rate of mineralization of root and top‐growth materials of alfalfa, white clover, annual lespedeza, perennial lespedeza, Kudzu, and tall fescue correlated closely with nitrogen content. Early immobilization of nitrogen occurred with organic materials with less, than 2.5% nitrogen. A net release of nitrogen occurred within 6 weeks from materials containing as little as 1% nitrogen. Added ammonium nitrogen was partially immobilized and then slowly released.