Alternative Uses, in and off-Field Managements to Reduce Adverse Impact of Crop Residue Burning on Environment: A Review

Residues of various crops are considered nuisance but they can be helpful in increasing organic matter in soil and better cycling of nutrients in soil if managed properly. Better management and utilization of crop residues (CR) is necessary for better productivity and quality of crops. Sowing into loose residues is the major issue in adapting the drill sowing method. Apart from the higher quantity of rice (192.82 mt) and wheat residue (120.70 mt), the residue of sorghum, maize, barley, chickpea, groundnut, rapeseed, mustard, sugarcane trash, potato, soybean, sunflower and some other minor cereals also contribute substantially towards total amount of about 462.93 million tonnes in India in 1997-98. Three quarters of the total residue is produced by rice, wheat and oil seed crops with remaining quarter coming from sugarcane and sorghum. Crop residue is important component of low external input for sustainable agriculture without sacrificing productivity. The crop residues left behind is considered as burden forcing farmers to burn them as cheap and easiest method with mistaken belief that it enhances the soil fertility and helps in controlling weeds, insects and pests. Different studies revealed that burning of residues causes air pollution and nutrient loss in soil. Improvements in soil properties and the sustainability in crop productivity could be achieved if CR are proper managed. Long-term field studies at sites carefully selected with variations in temperature, moisture, soil mineralogy and management of agricultural residues representing various cropping systems across regions should be identified and sustained. The possible benefits of crop residues for the improvement of degrading soil fertility would be completely understood only then. Owing to the competing requirements for such biomass for feed, fuel or building material, smallholder farmers typically find it difficult to maintain a soil cover for crop residue or a cover crop.