무기태 질소와 액상구비의 시용수준이 Orchardgrass의 건물수량에 미치는 영향

Effects of application rates of mineral N and cattle slurry on the dry matter yield of Orchardgrass

무기태 질소와 액상구비의 사용수준이 예취빈도를 달리한 Orchardgrass 초지의 건물수량에 미치는 영향을 조사한 바 사용수준과 예취번초간에서는 0.1% 수준, 사용빈도와 예취번초간의 교호작용에 있어서는 5 % 수준의 유의성이 인정되었다. 일반적으로 3회 예취구보다 4회 예취구에서 건물수량이 증가하였다. 무기태 질소의 경우는 사용수준(90-270 kg/ha)에 따른 건물수량에 있어서는 유의한 차이가 인정되지 않았다. 액상구비의 시용효과는 3회 예취구에서 사용수준 평균 91.4% (72.2-109.7%의 범위), 4회 예취구에서는 75.1% (48.3-107.9%의 범위)를 나타내었다. 연간 3-4회 예취하는 채초지에서는 액상구비의 적정 시용량은 $80-90m^3/ha$(240-270 N kg/ha)의 수준으로 추정되었고 이때 건물수량은 9.55-11.22ton/ha 이었다.

This experiment was to study the effects of application rates of mineral N and cattle slurry on the dry matter yield of Orchardgrass grown in different cutting frequency. Annual rates of mineral N of 0($N_0$), 90kg($N_1$), 180kg($N_2$) and 270kg／ha($N_3$) in 3 cuttings, and 0($N_0$), 120kg($N_1$), 240($N_2$) and 360kg/ha($N_3$) were applied as urea in 4 cuttings. Cattle slurry applied at rates of $30m^3(S_1)$, $60m^3(S_2)$ and $90m^3/ha(S_3)$, suppling 90kg, 180kg and 240kg N/ha in 3 cuttings, and at rates of $40m^3(S_1)$, $80m^3(S_2)$ and $120m^3/ha(S_3)$, suppling 120kg, 240kg and 360kg N/ha in 4 cuttings, respectively. The results were summarized as follows; 1. Mineral N and cattle slurry application rates(N), and cuts(C) were significant differences at the 0.1% level(p<0.001), and 5% level(p<0.05) for the interaction of $N{\times}C$ in both cuttings. 2. The annual dry matter yields obtained were 8.8ton-10.1ton/ha at rates of $N_1-N_3$, and 7.1ton-9.5ton/ha at rates of $S_1-S_3$ in 3 cuttings. The annual dry matter yields obtained were 10.9ton-13.9ton/ha at rates of $N_1-N_3$, and 6.9ton-11.2ton/ha at rates of $S_1-S_3$ in 4 cuttings, respectively. 3. Relative efficiency of cattle slurry N for the dry matter production of Orchardgrass pasture as compared to mineral N were 91.4%(ranged from 72.2% to 109.7%) in 3 cuttings, and 75.1%(ranged from 48.3% to 107.9%) in 4 cuttings, respectively. 4. The annual cattle slurry application rates required to maintain highest dry matter yields were estimated to be 90m3/ha(270kg N/ha) and 80m3/ha(240kg N/kg) in 3 and 4cuttings.