Pantnagar Journal of Research

Abstract

Optimizing nitrogen (N) use efficiency in rice requires effective management of crop–weed competition. A field experiment was conducted during the Kharif season of 2018 in SKUAST Kashmir to evaluate the interactive effects of nitrogen levels (0, 45, and 90 kg N ha^¹) and weed management practices on weed dynamics, nutrient partitioning, resource use efficiency, yield, and grain quality of basmati rice (Shalimar Sugandh 1). Weed interference significantly reduced grain yield (3.89 t ha^¹), crop nutrient uptake, and resource use efficiency, accounting for 11.78% nutrient loss to weeds. In contrast, application of penoxsulam @ 22.5 g ha^¹ effectively reduced weed biomass (16.74 g m^²), improved weed control efficiency (72.08%), and enhanced grain yield (6.46 t ha^¹), comparable to weed free conditions. Nitrogen application increased grain yield up to 6.49 t ha ^¹, with an agronomic efficiency of 17.55 kg grain kg^¹ N at 90 kg N ha^¹. Improved weed control significantly enhanced crop nutrient advantage and reduced nutrient losses, indicating a strong shift in resource capture towards the crop. Grain quality parameters remained largely stable across treatments, although gel consistency improved under higher nitrogen and effective weed control, suggesting enhanced starch deposition. The results highlight that maximizing nitrogen use efficiency and sustaining grain quality in basmati rice requires integrated nutrient and weed management, particularly early postemergence herbicide application to minimize competitive losses.