Effect of crop residue management on the yields of different crops and on soil properties

Abstract

The effects of chopped (6–9 cm) and unchopped (long) crop residues of wheat ( Triticum aestivum L.) and rice ( Oryza sativa L.) in corn ( Zea mays L.)— wheat and rice-wheat rotations on grain yield and soil properties were investigated in 27 field experiments during 9 years. Experiments on chopped wheat residue involved the treatments of two main plots with residue incorporation at 0 and 4 t/ha before sowing of corn and wheat and having subplots with 0, 40, 80 and 120 kg N/ha. The results obtained for 4 years showed that the incorporation of wheat residue not only improved the soil physicochemical properties but also increased the grain and stover yields of corn significantly. The yield obtained with 80 kg N in conjunction with 4 t/ha chopped wheat residue was identical to that with 120 kg N/ha alone. But the wheat yield was depressed significantly upon the incorporation of wheat residue before the sowing of wheat in all the years of investigation. The experiments on the management of unchopped wheat residue in corn-wheat rotation and of unchopped wheat (6 t/ha) and rice (12 t/ha) residues in rice-wheat rotation, involved three main treatments: physical removal, in-situ incorporation and in-situ burning of residues. Main treatments were tested at 60, 120 and 180 kg N/ha level over 5 years. Irrespective of N application, the residue management treatments had non-significant effects on the succeeding crop yield in all the years. Burning of residue improved the yield by about 0·2 t/ha, whereas residue incorporation did not affect the yield either of corn or rice. On the other hand, the wheat yield was depressed by 0·1–0·2 t/ha in both the rotations. The effect of applied N irrespective of residue management was significant in some years up to the level of 120 kg and in others, 180 kg N/ha.