Effect of Weed Management Practices and Fertilizer Levels on Crop Nutrient Uptake and Weed Nutrient Removal in the Hybrid Rice

Aim: Comparative evaluation of weed management practices and fertilizer levels on crop nutrient uptake and weed nutrient removal in the hybrid rice.

Study Design: The experiment was laid out in split-plot design with weed management in main-plot and fertilizer levels in sub-plot and was replicated thrice.

Place and Duration of Study: Experiment was performed during the kharif period of 2017 at the Research Farm, TCA, Dholi, Dr. Rajendra Prasad Central Agricultural University, Pusa, Samastipur (BIHAR).

Methodology: The experiment was performed with twelve treatments in a split plot design. The main plot comprised four different weed management practices and under the sub-plot there were three fertilizer levels. Rice hybrid “ARIZE-6444” was taken as the test variety. Observations of the crop and weeds during the experimental duration were recorded at regular intervals, to assess the probable relationship between growth attributes and the final yield. The significance of the treatment impact was examined by the F test.

Results: Among weed management practices, maximum uptake by rice with respect to nitrogen (152.85 Kg/ha), phosphorous (45.79 Kg/ha) and potassium (187.13 Kg/ha) and minimum removal by weed regarding nitrogen (1.30 Kg/ha), phosphorous (0.54 Kg/ha) and potassium (1.85 Kg/ha) was recorded in treatment hand weeding twice which was observed statistically at par with Bispyribac-sodium @ 25 g/ha + Pyrazosulfuron @ 25 g/ha at 25 DAT.

Among fertilizer levels, application of 150 per cent RDF registered the highest portion of nitrogen (130.52 Kg/ha), phosphorous (40.40 Kg/ha) and potassium (164.49 Kg/ha) uptake by rice crop and nutrient removal through weeds is nitrogen (10.65 Kg/ha), phosphorous (4.84 Kg/ha) and potassium (15.59 Kg/ha) of, and respectively.

Conclusion: Among different weed management practices combined application of Bispyribac-sodium @ 25 g/ha + Pyrazosulfuron @ 25 g/ha at @) DAT or hand weeding twice (20 and 40 DAT) was found effective in controlling weeds and increase in the quality and quantity of rice. Among fertilizer levels application of 125% RDF was found effective in increase in the yield, nutrient content of the crop and substantially reduction of nutrients removed by weed in rice field.