Effect of nitrogen levels and weed control methods on yield and economics of wheat under zero-tillage conditions

A field experiment was conducted during Rabi seasons of 2015–16 and 2016–17 to study the effect of nitrogen and weed control on wheat yield, nitrogen uptake and economics of wheat. The treatments comprised of 4 levels of nitrogen, viz. 90, 120, 150 and 180 kg/ha, and 5 weed control methods, viz. weedy check, hand weedings at 30 and 60 days after seeding (DAS), clodinafop + metsulfuron (60 + 4 g/ha), fenoxaprop + metsulfuron (120 + 4 g/ha) and sulfosulfuron + metsulfuron (25 + 4 g/ha). Weed density was reduced with increased rate of nitrogen from 90 to 180 kg/ha. Crop fertilized with180 kg N/ha was at par with 150 kg N/ha but produced significantly higher weeds biomass than the rest of the nitrogen levels. The uptake of nitrogen by weeds was significantly higher with 180 kg/ha than the other N-levels. Post-emergence spray of clodinafop + metsulfuron (60 + 4 g/ha) recorded significantly the lowest weed population followed by sulfosulfuron + metsulfuron (25 + 4 g/ha) and fenoxaprop + metsulfuron (120 + 4 g/ha). Hand weeding twice (30 and 60 DAS) recorded the significantly lowest weeds biomass, followed by clodinafop + metsulfuron (60 + 4 g/ha). Weedy check recorded significantly maximum amount of nitrogen uptake by weeds. Nitrogen applied at 180 kg/ha recorded the highest wheat grain yield (3.82 and 3.98 t/ha), crop nitrogen uptake (96.81 and 99.69 kg/ha), gross returns (? 73700/ha), net returns (? 49600/ha) and B:C ratio (2.06).