Comparative study on composition of soil aggregates with different land use patterns and several kinds of soil aggregate stability index

To analyze and compare the quality of soil aggregate under various conditions, and find more sensitive status index and research method of the aggregation, and reveal the effect and influence of human activities on soil quality, an experiment on vegetable garden soil and the orchard soil with different planting histories was conducted. Mean weight diameter (MWD), geometric mean diameter (GMD), dimension and moment method parameter were used to analyze the characteristics of aggregates composition variation of the two kinds of soil in the process of vibration screening. The results showed that: MWD and GMD as aggregate status index could basically reflect the difference of the soil aggregate levels only in the appropriate scope of vibration screening time. The credibility of using dimension for index to display the level of soil aggregate was questionable. Moment method parameter was more sensitive to characterize the level of soil aggregate. At the same time, the level of soil aggregate of both garden soil and orchard soil increased at first and then decreased with the increase of using term.