Influence of Melia dubia Spatial Configurations on Quantitative and Qualitative Performance of Hybrid Napier (Pennisetum purpureum x P. americanum) and Soil Biota Status

Study intended to develop suitable Melia dubia-hybrid Napier (HN) silvi-pasture and sole cropping systems through assessment of growth, physiology, forage yield, proximate and mineral principles of hybrid Napier under 5 years old M. dubia planted at 2 x 2, 3 x 3, 3 x 2, 4 x 4 and 4 x 2 m spatial configurations. Study revealed that growth, physiological attributes, fresh and dry forage production, and proximate and mineral matter principles (average of two years; three harvests in each year) were higher under silvi-pasture systems as compared to sole cropping. Among silvi-pasture, HN attained significantly maximum plant height and number of leaves under M. dubia (2 x 2 m)-HN, lengthiest leaf (96.76 cm) and widest leaf under M. dubia (3 x 2 m)-HN, and tillers under sole HN cropping system. Among studied physiological attributes, specific leaf weight was maximum in sole HN cropping, chlorophyll content index was maximum of forage from M. dubia (2 x2 m)-HN system, leaf area and leaf area index was maximum for clumps under M. dubia (3 x 2 m)-HN system. Significantly higher total fresh and dry forage yield was obtained from M. dubia (2 x 2 m)-HN and M. dubia (3 x 2 m)-HN, respectively. Significantly maximum dry matter and crude fibre was in forage from sole cropping system. However, maximum crude protein, ether extract, nitrogen free extract, ash and nitrogen were recorded in forage from M. dubia (2 x 2 m)-HN system. Whereas, phosphorus and potassium was higher in forage from M. dubia (3 x 2 m)-HN system. Integration of HN as understory crops, increased microbial populations in all land use systems.Among different silvi-pasture systems, closest spacing had more bacterial and actinomycetes populations, while fungi were highest under sole cropping. The study divulged out that tree-crop interactions under different M. dubia spatial configurations were positive. Hence, HN could be adopted as intercrop for higher forage yield and better nutritive quality.