Evaluation of Intercropping Sorghum × Sudangrass Hybrid (Sorghum bicolor) with Legume Crops Based on Growth Characteristics, Forage Productivity, and Feed Values at a Summer Paddy Field

Intercropping cereals with legumes is known to improve forage production and crude protein yield. Sorghum × sudangrass hybrids (SSH) have excellent dry matter content and high cultivation temperatures. In this study, we investigated the growth characteristics, forage productivity, and feed value of intercropping SSH with different legumes in rice paddy fields. We used five treatments in this study SSH monocropping and four intercropping treatments of SSH with, lablab, cowpea, sesbania, and two cultivars of soybean (Chookdu 1 and 2). SSH plant height was not significantly different between the monocropping and intercropping treatments. However, the plant heights of lablab, cowpea, and sesbania were significantly higher than those of the two soybean cultivars. The total dry matter yield (kg/ha) was significantly higher in SSH monocropping than in intercropping; among the intercropping treatments, the one with SSH and Chookdu 2 yielded the highest total dry matter yield. The SSH feed value was significantly different between the monocropping and intercropping treatments, although there were no differences between the intercropping treatments. Among the intercropped legumes, lablab showed the highest neutral detergent fiber and acid detergent fiber contents, and cowpea had the highest crude protein content. These results reveal that intercropping SSH with legumes in paddy fields could be a promising cultivation technique to maintain stable forage productivity.