Soil quality and production of low land paddy under agrisilviculture systems in acid soil of West Bengal, India

Abstract

Seven tree species (Terminalia arjuna, Lagerstroemia parviflora, Salix tetrasperma, Pongamia pinnata, Bombax ceiba, Bixa oreliana and Gmelina arborea) based agrisilviculture systems were established to test their compatibility with respect to production of rice and physiochemical status of soil in low land – paddy growing area of North Bengal, India. A gradual increase in biological yield was recorded with increase in distance from tree. Grain yield ranged from 3.21 t ha-1 in Pongamia at 1 m distance from tree to 4.94 t ha-1 at 3 m away from Bixa. Harvest index of paddy in control was higher (34.57) as compared to those intercropped with trees. Presence of trees significantly reduced PAR adjoining tree rows. The lowest PAR (1150 µmols-1m-2) was recorded at 1 m distance from Pongamia tree. The organic carbon content was greater in Terminalia (2.15 %) and least (1.19 %) in sub-surface soil layer of Salix based system. Microbial biomass carbon was greatest in surface soil of Terminalia (526 mg kg”1) followed by Gmelina (408.33 mg kg -1) and least in sub-surface soil of Salix (280 mg kg-1).