Impact of rice (O. sativa L.) straw incorporation induced changes in soil physical and chemical properties on yield, water and nitrogen–balance and –use efficiency of wheat (T. aestivum L.) in rice–wheat cropping system: Field and simulation studies

Abstract

CONTEXTDeterioration of soil physico–chemical properties as a result of puddling and burning of rice straw is one of the big challenges for the farmers in Indo Gangetic plains. OBJECTIVETo study the impact of rice straw incorporation persuaded changes in soil properties on yield, water and nitrogen use efficiency of wheat in rice–wheat cropping system. METHODSA field experiment, with split plot design and replicated thrice, was conducted with treatment combinations of four rates of rice straw incorporation, Rsti (0, 5, 7.5, 10 t ha−1) as main plots and four rates of fertilizer nitrogen, N (0, 90, 120 and 150 kg ha−1) as sub plots for ten years. Simulations with same treatments of Rsti and N along with three irrigation regimes, IW (240, 320 and 400 mm) were carried out for 30 years with calibrated and validated DSSAT–CSM–CERES–Wheat v4.75 model. RESULTS AND CONCLUSIONSThe results of field experimentation and model showed that the significant effect of Rsti on wheat yield was up to 7.5 t ha−1; Comparable yield to recommended practices (without crop residue) was realized with Rsti in conjunction with less IW and N, ensuing saving of 80 mm IW plus 30 kg N ha−1. Rsti increased water use efficiency via reducing evapotranspiration; and increased nitrogen recovery efficiency by increasing N uptake, and decreasing N leaching and NH3 losses. SIGNIFICANCEThe model based simulations signifies that Rsti into surface soil is a viable option in India and IGP as it enhances yield, water and nitrogen use efficiencies in wheat of rice–wheat system.