Weed Management Practices in Organic Rice System (Oryza sativa L.): An Evaluation of Combining Cultural Practices for Improved Productivity and Sustainability

A field experiment was conducted at Agronomy Research Farm of Narendra Deva University of Agriculture and Technology, Ayodhya (U.P.) during the kharif season of 2018–19 to evaluate effective weed management practices under organic systems in rice. In this experiment, seven treatments were examined in three replicates using Randomized Complete Block Design (RCBD). The soil of the experimental field was silty loam in texture. The rice variety NDR-2065 was transplanted. All nutrients were supplied through farm yard manure (75%) and vermicompost (25%). Results concluded that stale-seed bed+reduce spacing up to 25%+mulching with rice straw+1 hand-weeding at 50 days after transplanting (DAT) were most effective in controlling weeds, followed by hand-weeding at 25 and 50 DAT in rice. Grain (3.39 t ha-1), straw (3.96 t ha-1), and biological yield (7.35 t ha-1) were increased significantly under stale-seed bed+reduce spacing-up to 25%+mulching with rice straw+1 hand-weeding at 50 DAT, which was statistically similar with treatment hand-weeding at 25 and 50 DAT. The combination of a stale-seed bed, 25% reduced spacing, rice straw mulch, and one hand-weeding at 50 DAT resulted in a significant grain yield increase of 87% (p < 0.05) compared to the control, achieving a weed control efficiency of 75%. Not only did this treatment produce the highest gross return (₹67518 ha-1), net returns (₹33,907 ha⁻¹) and B:C ratio (1.01), it also showed that it was economically viable. Thus stale-seed bed+reduced spacing up to 25%+mulching with rice straw+1 hand-weeding at 50 days after transplanting was most effective at controlling the weeds and ultimately produced a more productive rice crop and proved to be more economically feasible than any other treatment.