Conservation Tillage and Weed Management Influencing Weed Dynamics, Crop Performance, Soil Properties, and Profitability in a Rice–Wheat–Greengram System in the Eastern Indo-Gangetic Plain

A three-year field experiment was carried out to assess the efficacy of various tillage and residue management practices, as well as weed management approaches, in a rice–wheat–green gram rotation. The treatments included: conventional till transplanted rice–conventional till wheat–fallow (T₁); conventional till transplanted rice–zero-till wheat–zero-till green gram (T₂); conventional till direct-seeded rice—conventional-till wheat—zero-till green gram (T₃); zero-till direct-seeded rice—zero-till wheat—zero-till green gram (T₄); zero-till direct-seeded rice + residue zero-till wheat + residue zero-till green gram (T₅). In weed management, three treatments are as follows: recommended herbicides (W₁); integrated weed management (W₂); and unweeded (W₃). The integrated weed management treatment had the lowest weed biomass, which was 44.3, 45.3, and 33.7% lower than the treatment W₃ at 30 and 60 days after sowing and harvest, respectively. T₁ grain and straw yielded more than T₂ in the early years than in subsequent years. The conventional till transplanted rice–zero-till wheat–zero-till green gram system produced 33.6, 37.6, and 27.7% greater net returns than the zero-till direct-seeded rice—zero-till wheat—zero-till greengram system, respectively. Conventional till transplanted rice–conventional till wheat–fallow had the biggest reduction (0.41%) in soil organic carbon from the initial value. The findings of the study demonstrated that adopting the transplanting method for rice, followed by zero tillage for wheat and green gram, enhanced productivity and profitability, while simultaneously preserving soil health.