오차드그라스의 예취빈도에 따른 무기태질소의 단기시용 효과 = Short-Term Effect of Mineral Nitrogen Fertilization under Various Cutting Frequencies on Orchardgrass(Dactlyis glomerata L.)

다국어 초록 (Multilingual Abstract)

A study was made to estimate the economic level(Necon.) of mineral nitrogen and a proper cutting frequency for the dry matter production of Orchardgrass (Dactlyis glomerata L.) during the harvested years in 1993∼1995. Annual mineral nitrogen 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 cuttings, respectively. The dry matter yields of all cutting frequencies in 1993 were significantly higher than in the other harvested years. Mean dry matter yield were 13.1, 12.7 and 14.3 tons ha-1 in 3, 4 and 5 cuttings, respectively. Higher efficiencies of dry matter production in response to mineral nitrogen application were recorded as 12.9 kg at level of 360 kg ha^(-1) yr-1 in 3 cuttings. 27.3 kg at level of 240 kg ha-1 yr^(-1) in 4 cuttings, and 20.5 kg at level of 150 kg ha-1 yr-1 in 5 cuttings, respectively. Significantly higher dry matter yields appeared as 4.6 tons ha-1 at 1st cut in 3 cuttings, 3.7 tons and 4.1 tons ha^(-1) at 2nd cut in 4 and 5 cuttings, respectively. The estimated marginal dry matter yields(Ymar.) were 11.7∼12.3 tons ha^(-1) at ranges of economic N level of 285.5∼316.6 kg ha^(-1) yr^(-1) in 3 cuttings, 10.4∼10.5 tons ha-1 at ranges of 176.7∼196.6 kg ha^(-1) yr^(-1) in 4 cuttings, and 11.2∼11.6 tons ha^(-1) at ranges of 246.1∼286.0 kg ha^(-1) yr^(-1) in 5 cuttings, respectively. Maximun dry matter yields(Ymax.) were 14.3 tons at the level of limiting N(Nmax.) of 379.5 kg ha^(-1) yr^(-1) in 3 cuttings. 11.1 ton at level of limiting N of 298.4 kg ha^(-1) yr^(-1) in 4 cuttings, and 12.3 ton at level of limiting N of 467.7 kg ha^(-1) yr^(-1) in 5 cuttings, respectively. Economic N level in all cuts were in the ranges of 85.1∼116.1 kg ha^(-1) cut^(-1) in 3 cuttings, 31.3∼69.7 kg ha^(-1) cut^(-1) in 4 cuttings, and 30.8∼81.4 kg ha^(-1) cut^(-1) in 5 cuttings, respectively.

목차 (Table of Contents)

• 목차
• ABSTRACT
• Ⅰ. 서론
• Ⅱ. 재료 및 방법
• Ⅲ. 결과
• 1. 예취빈도별 질소시비에 의한 연 건물수량의 변화
• 2. 예취빈도와 질소시비에 따른 질소 이용효율
• 3. 예취빈도와 질소시비에 따른 예취 시기별 건물수량의 변화
• 4. 예취빈도별 무기태 질소의 경제적 시비수준, 한계건물 수량, 한계시비수준 및 최대건물수량의 연간 차이
• 5. 예취빈도별 예취번초의 경제적 시비수준
• Ⅳ. 고찰
• Ⅴ. 적요
• 인용문헌