EFFECTS OF STRAW DECOMPOSITION ON AGGREGATE COMPOSITION AND AGGREGATE-ASSOCIATED ORGANIC CARBON IN DIFFERENT SOIL MINERAL TYPES
Applied Ecology and Environmental Research
Liu et al.: Effects of straw decomposition on aggregate composition and aggregate-associated organic carbon in different soil mineral types -6511 -APPLIED ECOLOGY AND ENVIRONMENTAL RESEARCH 18(5):6511-6528. Abstract. Straw is an important organic resource that could be recycled, however, few studies investigated the effects of straw decomposition on aggregate stability and organic carbon (OC) of different mineral soils. In this study, we conducted a constant temperature incubation experiment
... ation experiment for 120 days in three different mineral soils consisting of two treatments: control soil and straw-amended soil. The results showed that straw addition promoted a significant increase of >2 mm water-stable macroaggregates as well as a significant decrease of microaggregates (<0.25 mm) compared with control soils (P<0.05). From day 15 to day 120, the three straw-amended soils significantly increased in mean weight diameter (MWD) and geometric mean diameter (GMD). The OC concentration of different particle-size aggregates in strawamended soils increased significantly during the early 15 days of incubation, then gradually decreased during the later stages. After 120 days of incubation, the contribution of OC of macroaggregates to soil organic carbon in fluvo-aquic soil reached the highest (66.14%). Among them, the fluvo-aquic soil with 2:1 clay mineral showed better improvement of aggregate stability and OC concentration than red soil during straw decomposition. These results confirm the differences and benefits of straw application for soil structure and quality of different clay mineral types.