Effect of tillage and herbicides on grain yield and nutrient uptake by wheat (Triticum aestivum) and weeds

A field experiment was conducted during winter season of 2003-04 and 2004-05 on clayey soil to study the ef- fect of different tillage practices (zero tillage, zero tillage with chemically stale seed-bed, conventional tillage and deep tillage) and herbicides (clodinafop Q 0.06 kglha followed by 2,4-D Q 0.5 kglha, isoproturon Q 1.0 kglha + 2,4-D Q 0.5 kglha and weedy check) on nutrient depletion by weeds, and the grain yield and nutrient uptake by wheat (Triticum aestivum L. emend. Fiori & Paol.). The depletion of N, P and K by weeds and uptake by crop were more or less the same under zero, conventional and deep tillage systems. Clodinafop 0.06 kglha followed by 2,4-D at 0.50 kglha gave 45.88-47.05 and 63.20-66.08 per cent higher grain yield than isoproturon + 2,4-D and weedy check respectively. The N, P and K uptake by wheat increased by 44.29-51.24, 12.00-12.87 and 8.37-9.87 kglha due to application of clodinafop followed by 2,4-D, whereas isoproturon + 2,4-D increased the uptake by 10.85- 15.50, 3.12-4.63 and 2.31-2.89 kglha N, P and K respectively compared with weedy check. Maximum benefit: cost ratio was obtained with zero tillage along with application of clodinafop followed by 2,4-D.