Effect of Plant Density and Planting Pattern on the Growth Chracteristics , Dry matter Yield and Feeding Value of Sorghum -Sudangrass Hybrid

파종량과 재식양식이 수수-수단그라스계 잡종의 생육특성 , 건물수량 및 사료가치에 미치는 영향

The purpose of the experiment was to determine the effect of plant density and pattern on growth characteristics, total dry matter yield. protein yield and palatability of sorghum-sudangrass hybrid (Sordan 79). The main treatment was three levels of plant density (Skg, 15kg. 30kg/ha) and the sub treatment was two plant patterns of square and rectangular planting.The experiment was arranged as a split plot design and conducted on the Experimental Livestock Farm of Kon-Kuk Univ. in Chungju, 1989. The results obtained are summarized as follows :1. As the plant density was increased, plant length, leaf length, leaf width(P<0.05) and leaf number were gradually decreased, but in the same plant density, plant length, leaf length, leaf width and leaf number were generally increased in the rectangular plot. 2. In the first cutting time, the ratio of leaf was the highest at the rectangular plot of high density (30kg/ha, 25cm$\times$4cm), but in the second cutting time, the ratio of leaf was the highest at the square plot of medium density (15kg/ha, 14cm$\times$ 14cm). 3. The ratio of dead stubble after cutting was generally increased by increasing the plant density. Also, in the same planting density, the ratio of dead stubble was generally increased in the square plot. 4. The tiller number per plant tended to decreased by increasing thc plant density, and the tiller number was increased in the rectangular plot. In the same plant density. 5. Total fresh and dry matter yield were the highest at the rectangular plot of medium density (IS kg/ha, 33cm$\times$6cm) wholly, but the low density was shown the lowest.6. The crude protein content was increased by increasing the plant density per unit area(P<0.05) and the protein yield was also increased by increasing the planting density. 7. According to the increase of plant density, the stem was thinned, but NDF, ADF did not show different. The palatability was in the order of high (30kg/ha))medium (15kg/ha))low density(5kgiha) at the first cutting time, but it was in the order of high)low)medium density at the second cutting time.

본 실험은 재식밀도와 재식양식이 Sorghum-Sudangrass hybrid(sordan 79)의 생육특성, 건물수량, 조단백질수량, 기호성 등에 미치는 영향을 알아보고자 실시하였으며 그 결과를 요약하면 다음과 같다.1. 재식밀도가 높아짐에 따라 초장, 엽장, 엽폭(P<0.05), 엽수는 대체적으로 감소하였고, 같은 재식밀도에 있어서는 직사각형구에서 증가하였다.2. 1차 예취시 엽비솔은 밀식구중 직사각형구(30kg/ha, 25cm$\times$4cm)에서 가장 높게 나타났으나 2차 예취시에는 중식구중 정사각형구(15kg/ha, 14cm $\times$14cm)에서 높게 나타났다.3. 고사솔은 재식밀도가 증가될수록 높아졌으며 또한 같은 재식밀도라도 정사각형구가 높았다. 4. 분벽수는 재식밀도가 높아질수록 감소 되었고 같은 재식밀도에서는 직사각형구에서 증가되는 경향이었다. 5. 생초수량과 건물수량은 공히 중식구중 직사각형구(1.5kg/ha, 33cm$\times$6cm)가 가장 높았으며 소식구에서 가장 낮았다. 6. 조단백질 량은 재식밀도가 높아짐에 따라 높은경향을 나타냈으며(P<0.05) 조단백질수량도 재식밀도가 높아질수록 수되었다.7. 경의 굵기는 재식밀도가 높아짐에 따라 가늘어졌고 NDF, ADF함량은 뚜렷한 경향이 없었다. 1차 예취시에 있어서 기호성은 밀식구>중식구>소식구순이었으나 2차 예취시에는 밀식구>소식구>중식구순이었다.식구순이었다.