Influence of establishment methods and weed management practices on nutrient removal by weeds and uptake by rice in puddled lowland.

摘要

Field experiments were conducted at Tamil Nadu Agricultural University, Coimbatore, India during kharif 2008 and rabi 2008-09 to find out the nutrient removal by weeds and uptake by crop in puddled lowland rice under different rice establishment methods and weed management practices. The experiments were laid out in a strip plot design, replicated thrice. Four crop establishment methods (System of Rice Intensification (SRI), Transplanting, Direct Planting System (DPS) and Drum seeding) and four weed management practices (pre-emergence pyrazosulfuron ethyl 30 g ha-1 at 3 DAT/8 DAS+weeding with finger type double row rotary weeder at 40 DAT/DAS, weeding with conoweeder twice at 20 and 40 DAT/DAS, two hand weeding at 20 and 40 DAT/DAS and un-weeded control) were taken up for the experiments. Direct planting system recorded significantly lower N, P₂O₅ and K₂O removal by weeds due to lower weed density and dry weight and was followed by system of rice intensification during both the seasons. In weed management practices, conoweeder twice at 20 and 40 DAT/S registered conspicuously lesser nutrient removal by weeds than other treatments. SRI showed significantly higher uptake of N, P₂O₅ and K₂O by crop and consequently recorded significantly higher yield during both the seasons. In weed management practices, weeding with conoweeder twice at 20 and 40 DAT/DAS recorded significantly higher uptake of N, P₂O₅ and K₂O by crop and registered higher yield.