牛粪与秸秆、生物质炭混合堆肥施用对土壤有机碳特征的影响OA

Through field experiments,the effects of applying composts from cattle manure alone,cattle manure+straw,cattle manure+biochar,and cattle manure+straw+biochar on the content of or-ganic carbon and its components in surface(0-20 cm)and subsurface(20-40 cm)soils,as well as in soil aggregates of different particle sizes,were compared.The results indicate that,compared to the control(ck),all four compost treatments significantly increased the content of organic carbon,water-soluble organic carbon(WSOC),and humic acid carbon(HAC)in the soil and aggregate fractions.The treatment with cattle manure,straw,and biochar compost showed the highest increases,followed by the cattle manure and straw compost treatment.Both surface and subsurface soils exhibited an in-crease in the proportion of 2-0.25 mm aggregates and a decrease in the proportion of 0.25-0.053 mm aggregates.There were significant positive correlations between the content of organic carbon,WSOC,HAC,and humin carbon(HUC)in the aggregate fractions and the overall soil content of these components.These findings suggest that under compost application,physical protection by ag-gregates is a key mechanism for the stabilization of soil organic carbon.Under the conditions of this experiment,adding composts made from cattle manure,straw,and biochar can enhance the content of organic carbon in the soil and aggregates,with the cattle manure,straw,and biochar compost treat-ment being the most effective.Overall,the application of organic fertilizer is of great significance for increasing soil organic carbon content.