Effect of Establishment Methods and Residual Nitrogen on Moongbean in Wheat based Cropping Systems

Agricultural production faces challenges, such as soil depletion, declining yields and climate variability, necessitating sustainable practices. Conservation agriculture (CA) improves soil health, ecosystem conservation and resource efficiency but is underutilized in cereal-based systems in South Asia. Incorporating legumes, such as green gram into cropping systems enhances nitrogen turnover and soil health. This study examines the effects of CA practices and residual nitrogen on green gram performance and soil health in a wheat-green gram-maize cropping system.

A two-year field study (Rabi 2021-Kharif 2023) was conducted at Indian Agricultural Research Institute, New Delhi, on sandy loam soil. The experiment was conducted using a split plot design and replicated thrice. Main plot treatments comprised of three crop establishment methods: conventional tillage (CT), zero tillage with residue retention (ZT+R) and permanent raised beds with residue retention (PB+R), whereas subplot treatments consist seven nitrogen management (NM) strategies for wheat and maize (varying RDN levels with prilled urea or nano-urea). No nitrogen was applied to the green gram, relying on the residual nitrogen from the wheat, as phosphorus and potassium were applied as per recommendation.

Permanent raised beds with residue retention (PB+R) significantly improved plant height, biomass, LAI, yield and nitrogen uptake compared with conventional tillage (CT) and zero tillage with residue retention (ZT+R). Nitrogen management with 100% RDN enhanced the nitrogen uptake, chlorophyll content and protein content. PB+R with 100% RDN recorded significantly highest green gram yield (0.85 t ha^-1) and nitrogen uptake, attributed to improved root proliferation, water conservation and nutrient acquisition. permanent raised beds with residue retention along with 100% RDN also recorded the highest net returns and B:C ratio.