Residual effect of legumes on maize yield, nitrogen balance and soil organic carbon stabilization under legume - maize cropping systems

Inclusion of legumes in cereal based cropping system restores soil fertility and improves carbon storage and soil quality. In this background a field experiment was conducted in a strip-split plot design using three legume species viz., green gram, groundnut and cluster bean as vertical strip, two residue management practices i.e. residue removal (-R) and residue retention (+R) as horizontal strip, and three nitrogen levels i.e. 100%, 75% and 50% recommended rate of nitrogen (N) application in intersectional sub plots with four replications during summer 2017 and 2018. The grain and stover yield of maize, N uptake and soil properties were monitored after each crop harvest; soil nitrogen balance and soil organic carbon were estimated. Under 100% N fertilization, cluster bean - maize cropping system with residue (+R) recorded 12.78 and 9.78% higher maize grain and stover yield, respectively than without residue (-R) treatment. Highest available N (189.9 kg ha-1) and available P (54.5 kg ha-1) were registered under cluster bean- maize cropping system. Legume residue incorporation resulted 9.65, 8.46, 7.09 and 8.86% higher (p = 0.05) WBC content, WBC stock, available N and P contents over residue removal scenario. Annually, 1.71% added carbon converted into soil organic carbon. Legume residue retention and 100% recommended rate of nitrogen application enhanced nitrogen balance. Soil N balance was highest under groundnut - maize system (165 kg ha-1). Overall, for better soil health and optimum crop production, cluster bean - maize cropping system with legume residue retention and 100% N fertilization may be promoted in semi-arid Western India.