Nutrient uptake by wheat and associated weeds as influenced by management practices
1992
Johri, A.K. | Singh, G. | Sharma, D. (G.B. Plant University of Agriculture and Technology. Pantnagar (India). Department of Agronomy)
Reports on a field experiment conducted during November 1984 to May 1985 to evaluate the effect of row spacing, seed rate, sowing method and weed control measures on the uptake of nutrients by different categories of weeds, and the availability of nutrients to the crop. Closer row spacing, higher seed rate and cross-sowing significantly decreased the nutrient removal by grass and broad-leaf weeds, as well as by a sedge, compared with wider row spacing, normal seed rate and one-direction sowing, and resulted in higher nutrient uptake by the crop. Uncontrolled weeds over a period of 90 days depleted on average 69, 15 and 52 kg N, P and K/ha, resulting in 48, 41 and 54 % crop loss in the N, P and K in weedy plots, compared with the drop in weed-free conditions. The uptake of nutrients was greatest in grass weeds and least in the sedge; broad-leaved weeds removed nutrients at a moderate rate. Isoproturon at 0.5 and 1.0 kg a.i./ha reduced the nutrient removal by the different weed categories, leading to increase in nutrient uptake by the crop
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