Studies on the Grassland Management in Late-Autumn and Early-Spring III. Effect of fertilizer application time in spring on growth, crude protein content and yield of grasses for soiling

월동전후 초지관리에 관한 연구 III. 봄철 청예이용 초지에서 이른봄 추비시용시기가 목초의 생육과 조단백질함량 및 수량에 미치는 영향

This field experiment was carried out to determine the effects of fertilizer application time in spring on the growth, crude protein(CP) content and dry matter(DM) yield of grasses for soiling. Application times of fertilizer were March 10, 20, 30, April 9 and 19, and control (non-fertilized) plot was involved. All fertilized plots were also treated with single- and compound fertilizer. The first harvesting date for soiling was May 12, and the regrowth soiling yield was investigated on June 9, 1988. In all fertilized plots, the growth, DM yield, CP, CP yield and regrowth yield of gasses were significantly increased compared with control, and the best grass growth, DM yield, CP, CP yield and N recovery were observed on March 30 and April 9 among all fertilized plots. And there were not significant differences between singleand compound fertilizer treatment in grass growth, DM yield and CP content. On March 30 and April 9 in this experiment, the accumulated temperature was 120 and 200^{\circ}C.$ and the subsoil temperature at 10 cm depth was 8 and 10^{\circ}C.$. Considering the average meteorological condition in Suwon area, the optimum application time of spring fertilizer for soiling may be recommended from April 3 to April 10.