Harnessing productivity potential and rehabilitation of degraded sodic lands through Jatropha based intercropping systems

This paper evaluates an intercropping model with Jatropha curcas L. (JCL) as an alternative crop on degraded sodic land in north India. Monoculture of JCL has not proven economically viable in India in view of its poor yield; therefore, intercrops in between JCL plantations were tried to optimize land use efficiency. The results revealed that the planting of JCL at 3 × 3 m spacing with inter-cultivation of sweet basil-matricaria (SB-M) cropping system for four years was more economically viable than planting at 3 × 2 m spacing and the other rotations tested in the study. Improvements in soil properties in terms of soil pH, EC and organic carbon were found with the SB-M cropping system with JCL as the main crop. Maximum soil microbial biomass carbon was recorded with the SB-M cropping system followed by sorghum-wheat (S-W) and maize-linseed (M-L), and the lowest values were found in the control plot where no intercrop was planted in between JCL plants. This study shows that intercropping with JCL on sodic soils stimulated the soil microbial population, which in turn led to high biological activity in the rhizosphere soil. Growing of medicinal and aromatic crops as intercrops between JCL plantations for four years appears to be a more suitable land use system than JCL mono-cropping to obtain maximum income. Simultaneously a soil improvement due to intercropping provides a new opportunity for even more competitive land use systems in the future.