Impact of different nitrogen management options and weed competition periods on weed dynamics, productivity, and profitability of bread wheat

Two-year field studies were conducted to study the impact of different nitrogen (N) sources and weed competition periods on weed density and dry biomass, N uptake, yield, and grain quality of bread wheat. The relationship of dry biomass with different yield components of wheat was also assessed. Different N sources comprised of sugarcane press mud (SPM) and inorganic fertilizers (IF; diammonium phosphate (DAP); and urea). Wheat cultivar Galaxy-2013 was subjected to increasing periods of weed competition (30, 45, 60, and 75 days after sowing) and increasing duration of weed-free periods for the aforementioned intervals. Weedy check and weed-free plots were kept for comparison. Results revealed that application of SPM either alone or in combination with IF significantly reduced the weed density and the corresponding dry biomass in comparison to IF alone. Yield and quality of wheat under different N management options diminished with an increase in the weed competition period. Contrarily, the blended N application under weed-free conditions not only increased grain yield of wheat but also significantly enhanced carbohydrate, protein, and starch contents and N uptake compared with the application of IF and SPM alone under all weed competition periods. Economic analysis revealed that the blended N application was economically the most viable option. Application of SPM either alone or in combination with the IF reduced weed density and the corresponding dry biomass. However, SPM alone cannot meet the crop’s nutritional requirement as and when required. It is therefore concluded from this study that blended application of SPM and IF has the potential to suppress weeds besides improving crop growth, productivity, and profitability. The mechanism of suppression, however, needs to be explored.