Effect of organic materials on the composition characteristics of micro-aggregates in albic soils and their nutrient contents Effects of heavy metals pollution on paddy soil aggregates composition and heavy metals distribution Effects of different governance patterns of small watershed on fractal features of soil micro-aggregates in the hilly areas of central Sichuan Basin Composition and Fractal Features of Soil Micro-Aggregates in Camellia sinensis Plantations, Sichuan Province Effects of conservational tillage measures on distributions of organic carbon and nitrogen in soil microaggregates Effects of different fertilization on soil organic carbon distribution and storage in micro-aggregates of red paddy topsoil