[Response of Aggregate Distribution to Input Straw and Their Linkages to Organic Carbon Mineralization in Soils Developed from Five Different Parent Materials].

Development and the dynamics of stable aggregates in many soils are known to be closely related to the cycling as well as accumulation of soil organic carbon (SOC). This study explored the aggregation processes and distributions of soil organic carbon in soils developed from limestone (L), quaternary red earth (Q), granite (G), basalt (B), and tertiary red sandstone (T) subtropical China related to the addition of maize residues during 7 days and 184 days of incubation. The soils were sieved to<0.25 mm before incubation. We aimed to clarify the mechanisms underlying SOC mineralization across soils from the perspective of soil aggregate protection. Fractionation of the water stable aggregates showed that addition of maize straw promoted the formation of>2 mm and 2-1 mm aggregates, while only 1.0-0.5, 0.5-0.25 and <0.25 mm aggregates were detected in the absence maize straw. The proportion of macroaggregates as well as their stability was always higher in L, Q, and B developed soils than those in G and T developed soils. In amended soils, the accumulation of total SOC was much obvious in L, Q, and B developed soils than those in G and T developed soils, and these increases were mainly contributed by the >0.25 mm macroaggregate-associated SOC. This result indicated that>0.25 mm macroaggregates were important spots for SOC sequestration. Furthermore, the proportions of>0.25 mm macroaggregate-associated SOC were also significantly (