Abstract
Yield and digestibility of napiergrass (Pennisetum purpureum Schumach) were compared under three levels of manure input up to 490 ton FW/ha/year in two years, aiming at clearing environmental pollution caused by dung and at improving forage productivity. Plants were grown from May 14 to November 6 and cut only once on September 8 in 1993. In 1994, plants were grown under three cutting intervals and three regimes of manure inputs. With increasing manure input in 1993, annual dry matter yields (TDMY), annual yields of in vitro digestible dry matter (TIVDDM), nitrogen concentration, in vitro dry matter digestibility and cellular contents tended to increase, while neutral detergent fiber content tended to decrease. TDMY increased with delaying cutting, while TIVDDM was higher in cutting interval of two months than in every month and no-cutting, and TIVDDM increased with increasing manure input in all cutting plots. Thus, it was suggested that the high level of manure input can improve not only dry matter yield but also forage quality of napiergrass, although the effect of manure input to increase TDMY tended to reduce as the level of manure input was increased.
