Characteristics and Stability of Soil Aggregates in Tea Plantation

Soil aggregate stability as a key indicator of soil structure and erodibility to evaluate soil stability, is a product of interactions between soil environment, management practices, and land use patterns. The objective of this study was to analyze the distribution characteristics, characteristics of fractal features and stability of soil aggregates in tea plantations and eucalyptus plantations of Western Sichuan in China. The dry- and water-stable aggregate size distributions were determined by dry sieving and wet sieving methods. The results showed that soil structural properties in tea and eucalyptus plantations were similar. With increase in depth of soil layer, the aggregate stability of tea plantation soil became stronger. Comparative analysis of dry and wet sieving results showed that most of the aggregates in tea plantation soil were unstable. The soil aggregates >5mm and 0.5-0.25mm in size had higher stability, while those 2-1mm in size had lower stability. For tea plantation soil, the correlation coefficients between aggregate stability index and mean weight diameter, geometric mean diameter, fractal dimension were bigger under wet sieving than those under dry sieving. The results showed that aggregate stability index, mean weight diameter, geometric mean diameter, fractal dimension of water-stable aggregates could characterize soil aggregate stability in tea plantation ideally.