Abstract
In order to investigate the short-term effect of cattle slurry N application on dry matter yield of reed canarygrass(Phalaris arundinacea L.) in uncultivated rice paddy during the harvested years in 1993~1995. Annual cattle slurry N was applied at the levels of 0, 90, 180, 270 and 360 kg $ha^{-1}$ in 3 cuttings, 0, 120, 240, 360 and 480 kg $ha^{-1}$ in 4 cuttings, and 0, 150, 300, 450 and 600 kg $ha^{-1}$ in 5 cutting, respectively. The results were summarized as follows; 1. The dry matter yields of all cutting frequencies in 1993 were higher than in other harvested years. 2. Significantly higher dry matter yields were obtained as 13.10 tons $ha^{-1}$ at level of 360 kg $ha^{-1}\;yr^{-1}$ in 3 cuttings, 12.50-12.83 tons $ha^{-1}$ at levels of 360-480kg $ha^{-1}\;yr^{-1}$ in 4 cuttings, and 12.52-12.56 tons $ha^{-1}$at levels of 450-600 kg $ha^{-1}$ $yr^{-1}$in 5 cuttings, respectively. 3. Efficiency of dry matter production(kg DM $kg^{-1}$ N) to cattle slurry N application tended to decrease with higher levels of cattle slurry N application and cutting frequencies. Higher efficiencies of dry matter production to cattle slurry N application were obtained as 15.2 kg at N level of 90 kg $ha^{-1}\;yr^{-1}$in 3 cuttings, 19.8 kg at level of 120 kg $ha^{-1}\;yr^{-1}$ in 4 cuttings, and 10.0 kg at level of 150 kg $ha^{-1}\;yr^{-1}$ in 5 cuttings, respectively. 4. The highest relative yields(RY) in different cutting frequency were 38.1% for 2nd cut in 3 cuttings, 41.8% for 3rd cut in 4 cuttings, and 30.1% for 4th cut in 5 cuttings, respectively. 5. The estimated ranges of marginal dry matter yield(Ymar.) were 11.5~12.1 tons $ha^{-1}$ at the ranges of economic N level of 261.0~304.6 kg $ha^{-1}\;$yr^{-1}$ in 3 cuttings, 10.4~11.5 tons $ha^{-1}$ at the ranges of economic N level of 205~302.9 kg $ha^{-1}\;yr^{-1}$ in 4 cuttings, and 11.1~11.6 tons $ha^{-1}$ at the ranges of economic N level of 303.8~354.4 kg $ha^{-1}$ 5 cuttings, respectively. 6. Ranges of economic slurry N level(Necon.) in all cuts were 67.9~95.0 kg $ha^{-1}$ in 3 cuttings, 14.3~119.8 kg $ha^{-1}$in 4 cuttings, and 50.9-125.2 kg $ha^{-1}$ in 5 cutting, respectively. 7. The 3 cuttings per annum was a proper cutting frequency for the increase in dry matter production of reed canarygrass using uncultivated rice paddy.
유휴논토양에서 reed canary grass를 재배하였을 때 액상구비의 단기간(3년간) 시용효과를 조사하였으 며, 그 결과를 요약하면 다음과 같다. 1. 모든 예취빈도에서 1993년의 건물수량이 다른 재배년도보다 많았다. 2. 액상구비의 시용수준별 평균 건물수량은 3회 예취구의 360 kg $ha^{-1}\;yr^{-1}$ 수준에서 13.10 ton $ha^{-1}$, 4회 예취구의 360~480 kg $ha^{-1}\;yr^{-1}$ 수준에서 12.50~12.83 ton $ha^{-1}$ 5회 예취구의 450~600 kg $ha^{-1}yr^{-1}$ 수준에서 12.52~12.56 ton $ha^{-1}$로 유의하게 많았다. 3. 건물생산 효율(kg DM $kg^{-1}$ N)은 액상구비의 시용수준과 예취빈도가 높을수록 낮아지는 경향이었다. 3회 예취구의 90 kg $ha^{-1}\;yr^{-1}$ 수준에서 15.2 kg, 4회 예취구의 120 kg $ha^{-1}\;yr^{-1}$ 수준에서 19.8 kg, 5회 예취구의 150 kg $ha^{-1}\;yr^{-1}$ 수준에서 10.0 kg을 나 내어 건물생산 효율이 가장 높았다. 4. 예취번초별 상대수량은 3회 예취구의 2번초가 38.1%, 4회 예취구의 3번초가 41.8%, 5회 예취구의 4번초가 30.1%로 가장 높았다. 5. 액상구비의 경제적 시용수준의 범위는 연간 평균 3회 예취구에서 261.0~304.6 kg $ha^{-1}\;yr^{-1}$, 4회 예취구에서 205.8~302.9 kg $ha^{-1}\;yr^{-1}$, 5회 예취구에서 303.8~354.4 kg $ha^{-1}\;yr^{-1}$로 추정되었고 이때 얻어지는 한계수량은 3회 예취구에서 11.5~12.1 ton $ha^{-1}$, 4회 예취구에서 10.4~11.5 ton $ha^{-1}$, 5회 예취구에서 11.1~11.6 ton $ha^{-1}$으로 추정되었다. 6. 예취번초의 경제적 시용수준의 범위는 3회 예 취구에서 67.9~95.0 kg $ha^{-1}$, 4회 예취구에서 14.3~119.8 kg $ha^{-1}$, 5회 예취구에서 50.9~125.2 kg $ha^{-1}$였다. 7. 건물수량에 대한 액상구비의 시용효과가 가장 높았던 예취빈도는 3회 예취구였다.
