Influence of different legumes on nutrient content and soil biological health in basmati rice-based cropping systems

To evaluate the long-term effects of legume integration in basmati rice–based systems, five production systems—fallow, basmati rice–wheat–dhaincha (Sesbania aculeata), basmati rice–kabuli chickpea–mung bean, basmati rice–chickpea–mung bean, and basmati rice–berseem–mung bean were assessed in a randomized block design with four replications during 2016–2023. The results showed that legume inclusion significantly improved yield-attributing traits, including tillers/m², panicle/m2, and grains/panicle. Among the systems evaluated, basmati rice–berseem–mung bean consistently performed best, registering 4.5% higher tiller density and 6.3% more grains/panicle compared with the basmati rice–chickpea–mung bean system. Grain and straw concentrations of N, P, and K were the highest under the basmati rice–berseem–mung bean and basmati rice–wheat– dhaincha systems. Soil biological properties followed similar trends, with the highest microbial biomass carbon (205.75 μg/g) and microbial biomass nitrogen (19.48 μg/g) recorded under the basmati rice–berseem– mung bean system in the 0–15 cm soil layer. Although microbial activity declined with soil depth, it remained consistently higher under legume-based systems than under fallow. The findings indicate that inclusion of berseem or dhaincha in basmati rice–based cropping systems enhances yield attributes, nutrient contents, and soil biological health. Therefore, integration of berseem (winter season)/ dhaincha (summer season) is recommended as a sustainable intensification strategy for efficient basmati rice production in the Indo-Gangetic Plains.