월동전후 초지관리에 관한 연구 VII. Orchargrass 채초지에서 이른 봄 질소시비시기와 질소비종이 목초의 생육과 수량 및 사료가치에 미치는 영향

Studies on the Grassland Management in Late-Autumn and Early-Spring VII. Effect of N application time and N fertilizer kind in early spring on grass growth, yield and nutritive value in orchardgrass meadow.

This field experiment was carried out to determine the effects of nitrogen(N) application time (March 30, April 9 and April 19) and N fertilizer kind (urea and ammonium sulfate) in early spring on the grass growth, dry matter (DM) yield, crude protein (CP) content, CP yield (CPY), acid detergent fiber (ADF) content, DM digestibility (DMD) and N recovery in orchardgrass (Dactylis glomerata L.) meadow for soiling, 1989. The amount of N applied in early spring was 70 kg $ha^{-1}$, and non-fertilized plot was involved as control. In all fertilized plots the growth, DM yield, CP, CPY and regrowth yield of grasses were significantly increased compared with control. The best grass growth and DM yield were observed on March 30, and the best CP, CPY and N recovery were observed on April 9 among all fertilized plots. Also there were not significant differences between urea and ammonium sulfate fertilizer in grass growth, DM yield, CP, CPY, ADF, DMD and N recovery. In Suwon area, therefore, the optimum time of N application for soiling in early spring may be recommended early April, regardless of fertilizer kind of N.