Coupled Effects of Film Mulching and Straw-derived Carbon Inputs on Soil Aggregate Characteristics and Crop Yields in Semiarid Areas
[Objectives]This study aimed to provide a scientific basis for optimizing appropriate film mulching practices to improve productivity and protect the environment in dryland farming.[Methods]A complete random two-factor field experiment was conducted in Pengyang,Ningxia Province to investigate the coupled effects of mulching(started in 2012)with different straw-derived carbon inputs on the soil aggregate characteristics,organic carbon content,and maize yield.Specifically,the mulching method was the main factor and the straw return form was the sub-factor.Six treatments were established as follows:straw return with film mulching(PS),biochar return with film mulching(PC),no-return with film mulching,straw return without mulching(TS),biochar return without mulching(TC),and no return without mulching.[Results]The results indicated that each straw and biochar return treatment significantly(P<0.05)improved the soil aggregate distribution and stability of each particle size,and the aggregate content>0.25 mm increased significantly(P<0.05)by 47.32%on average.Compared with the no-mulching treatment,the mean weight diameter and geometric mean diameter of the soil particles increased by 9.19%and 4.15%,respectively,under the double ridge-furrow mulching treatments.The organic carbon content of the 0-60 cm soil layer increased significantly(P<0.05)under each straw and biochar return treatment compared with the no-return treatments,where the contents were 2.60%and 2.73%higher under PC and TC than PS and TS,respectively.The aggregate organic carbon contents under each treatment increased as the aggregate particle size increased.Also,the straw and biochar return treatments significantly increased the organic carbon content of aggregates,whereas the contents decreased under double ridge-furrow mulching treatments.Structural equation modeling showed that the straw return form,mulching method,and soil organic carbon content could significantly promote yield increases,while the straw and biochar return treatments significantly increased(P<0.05)the corn yield in film-mulched fields by 14.6%on average.However,the yield increase did not differ significantly between the straw return treatments and biochar return treatments.[Conclusion]In conclusion,double ridge-furrow mulching and straw carbon input treatments significantly improved the soil stability,soil organic carbon content,crop yield,and the coupled effect of the double ridge-furrow mulching and biochar return had a positive effect on improving the farmland soil quality and fertility.
万方数据
维普
