Effects of wheat residue management in wheat/corn vs. wheat/clover cropping systems on yield and quality of crops and soil fertility

This experiment was conducted to investigate the effects of wheat residue management in Wheat/Corn (conventional) versus Wheat/Clover(new) cropping systems on yield and quality of crops and soil fertility. The experimental design was RCBD in strip plot arrangement in time with two factors and three replicates in permanent plots. The factors studied were wheat residue managements in three levels of burning, complete removal and 30% soil incorporation and cropping sequences in eight levels of wheat/clover, wheat/corn and six different sequences of wheat as base with clover and corn in three crop seasons. In the 4th crop season the spring wheat cultivar Pishtaz sowed to study the after effects of the cropping systems. According to the results continuous conventional cropping system of Wheat/Corn can result in soil degradation and system instability by quatitative and qualitative traits in the long run. The results of C/N ratio as a soil quality indicator showed that the best cropping system for improving the two components of this ratio as C and N should consider both soil incorporation of the wheat residue instead of burning and the introduction of the berseem clover to the new cropping system of Wheat/Clover-Wheat/Corn instead of the old conventional cropping system of Wheat/Corn. Definitly, this newly four crops in two years cropping system should be continued for more than a cycle to enhance the physical, chemical and biological status of the soil and many good consequences for the next years. Based on the results of economic analysis, the treatments of ( management of 30% soil incorporation with cropping pattern wheat/corn, wheat/clover, wheat/corn) selected the best and recommended. Benefit_cost ratio of this treatment was estimated 3.11, that is more than other treatments. Net present value of this treatment was estimated 398 million rials.