Effect of Tree-Crop Combinations and Nitrogen levels on velvet bean (Mucuna Pruriens L.) grown in Agrihorti-Silvi-Pasture system of Agroforestry in mid Himalayan Region

Abstract

Investigations on effect of tree-crop combinations and nitrogen levels on growth, biomass and seed yield of Mucuna pruriens L. were carried out during 2004-2005 and 2005-2006, in experimental farm of Department of Silviculture and Agroforestry, Dr. Y. S. Parmar University of Horticulture and Forestry, Nauni, Solan, Himachal Pradesh. The tree-crop combinations were T1 (Peach + Grewia + Setaria + M. pruriens), T2 (Peach + Morus + Setaria + M. pruriens), T3 (Peach + Setaria + M. pruriens), T4 (Grewia + Setaria + M. pruriens), T5 (Morus + Setaria + M. pruriens) and T6 (M. pruriens, sole crop). Its length, leaf area and leaf area index was significantly affected due to tree-crop associations giving maximum values as 3.60m, 276.30cm2/leaf and 2.53, respectively under sole cropping system. The nitrogen dose of 120kg/ha produced longest vine (3.80m), with leaf area 330.00cm2/leaf and leaf area index of 2.93. The above ground biomass was significantly higher (15.15t/ha) under sole cropping system followed by T2, T3, T4, and T5, suggesting suitability of tree crop systems for cultivation under these systems too. Similarly, below ground biomass was significantly higher (0.29t/ha) from open grown crop, nevertheless, tree-crop combinations T1, T2 and T5 gave biomass at par. Total biomass was not affected due to various tree-crop treatments. The nitrogen dose 120kg/ha gave maximum above ground (16.76t/ha), below ground (0.30t/ha) and total biomass (17.07t/ha). Although the tree-crop combinations affected biomass yield significantly however, seed yield did not have significant effect. The seed yield ranged 2.17 to 2.21t/ha. The N dose of 120kg/ha gave maximum (2.38t/ha) seed yield. The N levels did not show optimum level. Both tree-crop combinations as well as N doses failed to affect L-DOPA content estimated in the seed. However, L-DOPA content ranges from 4.58 to 5.05 per cent on dry seed weight basis. The L-DOPA content was same in seeds produced from open grown and seeds produced from plants grown under different Agroforestry Systems. Thus, Mucuna can be grown under Agroforestry Systems and fertilizers application to get higher biomass and seed yield without any changes in the active constituent.