Effects of dairy cattle manure and chemical fertilization input on productivity and

digestibility of napiergrass were studied in plant grown from rooted tiller. In 1993 and

1994, napiergrass was grown with three levels of manure fertilizer input, and the aftereffect

of manure fertilizer was continuously examined in 1995 and 1996. The total

amounts of manure input in fresh weight, in 1993 were 10, 250 and 500 ton/ha for Lplot,

M-plot and H-plot, respectively and those in 1994 were 10, 125 and 250 ton/ha for

the L-plot, M-plot and H-plot, respectively. On the other plot, three levels of chemical

fertilizer (120, 600 and 1200 kg N/ha for the L-plot, M-plot and H-plot, respectively)

were applied in 1996 to compare with the after-effect of the manure fertilization plots.

The result showed that total dry matter weight and total in vitro digestible dry matter

yield as examined for the after-effect of the previous year’s manure fertilization were

higher than those by the manure fertilizer input, but were not significantly different

than those by chemical fertilizer input in the highest level. Furthermore, the differences

of in vitro dry matter digestibility of plant between every experimental year were not

significant. It was concluded that, the decomposition of the organic fertilizer in manure

is slower than that of the chemical fertilizer