Bio-agronomic evaluation of forage sorghum-legumes binary crops on haplic yermosol soil of Pakistan

The proportionate share of binary crops in mixed intercropping systems is crucial for boosting the productivity and nutritional quality of forage. This field trial aimed to investigate the response of seed blended crops of forage sorghum and legumes (soybean, cowpea and cluster bean) to varying seed proportions (100:35, 100:65 and 100:85), while their solitary crops were planted for comparison. Agronomic, physiological and agro-qualitative traits were taken as the experimental variables. Sorghum sown as a binary crop with legumes resulted in a significant (p<0.05) decrease of green biomass yield (15-38%) compared to the solo sorghum. In intercropping, soybean recorded 44% less yield, while green forage biomass of cowpea was decreased by 27%. However, the seed blended crop of sorghum-cowpea in 100:65 seed proportion recorded significantly (p<0.01) higher biomass (30%) than the mono culture of sorghum. The mixed seeded crop of sorghum and soybean in 100:85 seeding ratio was instrumental in improving the crude protein and lowering the crude fiber content of mixed forage. Sorghum-cowpea binary crop gave the maximum ether extractable fat and total ash of mixed forage, while the solo sorghum had the lowest nutritional quality. Thus, seed blending of sorghum and cowpea in 100:65 seed blending ratio may be suggested owing to higher productivity in irrigated Haplic Yermosols soil under semi-arid climatic conditions. (author)