Crop Residues Management for Rice-Wheat Cropping System in Saline-Sodic Soil

Abstract

Series of field experiments were conducted to evaluate the long term effect of gypsum and crop residue on crop yield and soil health in rice-wheat crop rotation system in salt affected soil. A saline-sodic field having <TEX>$EC_e$</TEX> (electrical conductivity of the saturation extract) 4.77 (<TEX>$dSm^{-1}$</TEX>); pH (<TEX>$H_2O$</TEX>) 8.96; SAR 43.78 (<TEX>$mmol\;L^{-1}$</TEX>) and gypsum requirement (G.R.) 2.86 (Mg <TEX>$acre^{-1}$</TEX>) was selected on Soil Salinity Research Institute Farm. Five treatments consisting of (<TEX>$T_1$</TEX>) control, (<TEX>$T_2$</TEX>) gypsum at 100% G.R., (<TEX>$T_3$</TEX>) gypsum at 25% G.R. + wheat straw at <TEX>$3Mg\;ha^{-1}$</TEX>, (<TEX>$T_4$</TEX>) gypsum at 25% G.R. + rice straw at <TEX>$3Mg\;ha^{-1}$</TEX>, (<TEX>$T_5$</TEX>) gypsum at 25% G.R.+ rice and wheat straw at <TEX>$3Mg\;ha^{-1}$</TEX> were replicated four times under completely randomized block design. The data indicated that grain and straw yield of rice and wheat was significantly (P<0.05) increased by all the amendments used either single or in combination. <TEX>$T_2$</TEX> (gypsum at 100% G.R.) significantly (P<0.05) increased grain and straw yield of rice and wheat crops followed by <TEX>$T_3$</TEX> (gypsum at 25% G.R. + wheat straw at <TEX>$3Mg\;ha^{-1}$</TEX>) when compared with control. Soil properties were also improved by used amendments, pronounced decreased in <TEX>$EC_e$</TEX>, <TEX>$pH_s$</TEX> and SAR were recorded in <TEX>$T_2$</TEX> followed by <TEX>$T_3$</TEX>. The efficiency of the treatments could be arranged in following order gypsum at 100% G.R.> gypsum at 25% G.R. + wheat straw at <TEX>$3Mg\;ha^{-1}$</TEX> > gypsum at 25% G.R. + rice and wheat straw at <TEX>$3Mg\;ha^{-1}$</TEX> > gypsum at 25% G.R. + rice straw at <TEX>$3Mg\;ha^{-1}$</TEX> > control.