Effects of Long-term Subsoiling Combined with Straw Returning on Carbon Sequestration Capacity and Inorganic Stability Mechanism of Soil Aggregates
The effects of long-term tillage and straw returning on soil aggregate carbon sequestration capacity was analyzed,the inorganic stability mechanism of Fe and Al oxides in aggregates was explored,and theoretical basis for selecting appropriate farmland management measures was provided.Four treatments were set up in the experiment including subsoiling with straw returning(STs),subsoiling without straw returning(ST0),no-tillage with straw returning(NT,)and no-tillage without straw returning(NT0).The water-stable aggregates were measured by wet sieve method.Soil organic carbon and aggregate organic carbon were measured by TOC analyzer.Various forms of iron aluminum oxides were measured by colorimetric method.The effect of four treatments on each index was analyzed and compared.The results showed that compared with subsoiling,the mean weight diameter and geometric mean diameter in no-tillage were increased by 18.6％ and 6.8％,respectively.Compared with no-tillage,the soil organic carbon of＞2,1-2,0.5-1,0.25-0.5 and 0.106-0.25 mm in subsoiling was increased by 27.9％,28.8％,16.9％,11.0％ and 5.5％,respectively.The total carbon storage of subsoiling was increased by 11％ than that of no-tillage.The total carbon storage of straw returning increased by 11％ than that of no straw returning.The content of free iron oxide in the surface soil was increased by 50％ than that of other treatments.Compared with no-tillage,the amorphous iron and complex aluminum in subsoiling were increased by 43％ and 65％,respectively.Therefore,long-term subsoiling combined with straw returning could effectively improve soil carbon sequestration capacity and inorganic stability of aggregates.
subsoilingstraw returningaggregatecarbon reserveiron and aluminium oxidesoil carbon sequestration capacityinorganic stability of aggregates
万方数据
维普
