Influence of summer legume residue recycling and varietal diversification on productivity, energetics, and nutrient dynamics in basmati rice–wheat cropping system of western Indo-Gangetic Plains

ABSTRACT

A field experiment was conducted on summer mungbean residue recycling (SMBRR) and basmati rice–wheat cropping system (BRWCS) at New Delhi, India. The SMBRR enhanced the system productivity and net returns by ∼19.1% and 22.1% compared to summer fallow (SF) with highest magnitude under genotypic sequence of P 2511/HD 2967. Two genotypes each in basmati rice (PB 1 and P 2511) and wheat (HD 2967 and HD 2733) responded well to SMBRR with respect to grain yield efficiency index (GYEI) ≥ 1.0. SMBRR also registered ∼13.5% higher microbial biomass carbon (MBC) than SF. Soil organic carbon (SOC) storage also increased by ∼6.8% in 0–30 cm soil layer. The rice–wheat–summer mungbean system produced significantly highest energy efficiency compared to the rice–wheat–summer fallow system with highest values under genotypic sequence of P 2511/HD 2967 as a result of better yield expression. Overall, SMBRR with suitable genotypic sequence improved the system productivity, profitability, and nutrient dynamics in BRWCS, which are vital for long-term sustainability of this system.

KEYWORDS:

• basmati rice–wheat cropping system
• genotypic diversification
• grain yield efficiency index
• mungbean residue recycling
• nutrient dynamics
• productivity