Effect of alley management on root growth and distribution of Leucaena-based agroforestry system under rainfed condition of central Uttar Pradesh

The root distribution and development were studied under Leucaena-based alley cropping system with maize (Zea mays L) and mustard [Brassica juncea (L) Czernj. & Cosson] during two consecutive years of 1996–97 and 1997–98 at Soil Conservation and Water Management Research Farm of C.S. Azad University of Agriculture and Technology, Kanpur under rainfed condition. The Leucaena leucocephala (Lam.) de. Wit. hedgerows were established at alley widths of 4.0 m and 6.0 m having an intra-row spaces of 0.5, 1.0 and 1.5 m. In this study, two moisture conservation practices, viz. insitu application of pruned lopping biomass used as mulch and its alternate use as fodder (no mulch) were adopted. Higher crops yield were recorded in wider inter-row spacing (6.0 m) with closest intra-row spacing (0.5 m) and mulch treated plots. However, higher yield of Leucaena biomass was obtained from closely planted Leucaena with organic mulch treated plots. The wider alley spacing (6.0 m) exhibited decreased root depth and improved number of roots, spread of roots plant⁻¹and weight of roots plant⁻¹as compared to alley width of 4.0 m in maize, mustard and Leucaena crops, whereas closer intra-row spacing of 0.5 m showed the poorest root development while best development of roots plant⁻¹ was observed in 1.5 intra-row spacing in all the crops during both the years. In-situ application of pruned lopping biomass as mulch decreased the root depth but increased the number of roots, spread of roots plant⁻¹ and fresh as well as dry weight of roots plant⁻¹ over its alternate use as fodder (without Leucaena mulch) in maize, mustard and Leucaena.