Rice residue management, Wheat yield, Soil fertility, Net monetary return
Effect of rice residue management practices (removal, burning and incorporation), weed control measures (weedy check and herbicide) and nitrogen levels (60, 120 and 180 kg/ha) on the weed infestation, wheat yield and fertility status in a swell-shrink black cotton soil was studied during 2003-06. The herbicide treatment included application of isoproturon 1.0 kg/ha in the 1st year and tank mix of isoproturon 0.75 kg + 2,4-D 0.5 kg per hectare during the subsequent years. Residue incorporation reduced weed density, especially of Phalaris minor, resulting highest wheat yield during 2nd and 3rd year. Residue incorporation gave highest net monetary return of Rs. 57781 followed by Rs. 51440 and Rs. 48081 per hectare in the burning and straw removal treatments, respectively. The highest B:C of 6.79 was also recorded in the residue incorporation treatment followed by 6.19 and 3.86 in the burning and straw removal treatments, respectively. Herbicide application increased wheat yield and the net monetary return (B : C ratio). Irrespective of straw management practices, no increase in wheat yield was recorded beyond the N dose of 120 kg/ha. Compared to burning, the incorporation of rice straw significantly increased the organic C, and the bacterial and fungal population in soil. It was concluded that rice straw incorporation 5 t/ha was best among the given straw management practices in terms of weed density reduction, improved soil health, increased wheat yield, monetary return and B : C ratio.