Melia dubia tree spacing influence growth, yield and proximate principles of Sorghum bicolor x Sorghum bicolor var. sudanese and soil microbial status

Abstract

Present study was carried out to develop suitable Melia dubia­­­Sorghum bicolor x Sorghum bicolor var. sudanese (Sorghum sudan grass; SSG) silvi-pasture system in randomized block design with 6 treatments viz., LU (land use)1 to LU₅ having M. dubia spacing of 2x2, 3x2, 3x3, 4x2 and 4x4 m with SSG as intercrop and LU₆ as sole SSG, with 4 replications. Land use systems had significant effect on growth, physiology, forage production, and nutritive value of SSG. The results showed that maximum fresh (64.20 t ha^-1) and dry forage yield (15.93 t ha-1) was obtained from M. dubia (4 x 2 m)-SSG silvi-pasture. Significantly maximum dry matter (25.28%) and ether extract (2.69%) was in forage from M. dubia (4 x 2 m)-SSG system. However, crude protein (8.50%), nitrogen (1.36%) potassium (3.48%) contents were highest in forage from M. dubia (2 x 2 m)-SSG system. Dry matter and ash content was higher under wider M. dubia spatial geometries and sole cropping. The fungal and bacterial populations were affected by the M. dubia spatial configurations and count increased after SSG intercropping, except actinomycetes, in all LU systems. Among silvi-pasture and sole SSG, microbial population count was higher in closest spacings.