EFFECTS OF ANIMAL MANURES ON FORAGE YIELD, QUALITY OF FORAGE MAIZE AND SOIL FERTILITY

Animal manure is an organic fertilizer to maintain soil fertility. Objectives of this experiment were to determine effects of anmimal manures on forage yield and quality of forage maize (Zea mays) and to determine if heavy metal, Cu, was accumulated in corn plants or soil applied with Cu -containing animal manures. Corn, CV. Tainung no. 351, was planted in fall 1987, spring and fall 1988 and spring 1989, respectively. Cattle and hog manures containing N 100, 200 and 300 kg/ha added with chemical fertilizer were applied, or cattle and hog manures containing N 400 kg/ha were applied only. Chemical fertilizer treatment was used as control. The amounts of N, available P and K were increased in soil when cattle and hog manures were applied. The Cu level in soil was not enhanced when Cu-rich hog manure was applied. Forage yield was the highest among the treatments as hog manure was applied only. Higher yield was obtained in fall crop season than in spring crop season. No difference in Cu level was observed between cob and straw. The Cu level in whole plant was not affected by kinds and amounts of manures applied. Crude protein in plants was not significantly different among manure treatments except for that applied with cattle manure only. The levels of P2O5 and K2O in plants were increased when more cattle or hog manures were applied. The percentages TDN were also not significantly different among manure treatments. It showed that cattle or hog manure applied in soil could increase forage yield and quality of forage maize and improve soil fertility. Further, no Cu accumulation was observed in both corn plant and soil. It was suggested that animal manure might be applied in soil to maintain forage productivity and soil fertility.