Papers by Author: Shu Qin He

Abstract: Based on the determination method of the comprehensive domestic and international surface roughness, by the method of indoor artificial rainfall, the determination of soil surface roughness had been studied from the measurement accuracy, time-consuming and resolution. The results showed that the laser scanner method was the best to determine the surface roughness, followed by pin meter method, the roller chain meter method, and the ruler was the worst. The results of determination had the better correlation between the laser scanner method and the roller chain meter method before rainfall, however they had poor correlation after rainfall. They had the better correlation between the laser scanner method and pin meter method both before rainfall and after rainfall. And on this basis, the relationships were established among the different methods. The results provide theory basis for the further study on soil surface roughness. At the same time, it would serve for harnessing soil and water loss of the slope farmland in Loess Plateau.

Abstract: Land use patterns effect on soil anti-erodibility was studied by the combinative means of field investigation and laboratory analysis in low mountain-hilly region. The results showed that he five land use patterns had high proportion of aggregates at the size of >2 mm after dry sieving and had high proportion of aggregates at the size of <0.5 mm after wet sieving. Soil dispersion was mainly reflected in aggregate at the size of 0.05- 0.001 mm under different land use patterns. It was significantly different to land use patterns effect on soil anti-erodibility. Soil anti-erodibility in Chinese fir plantation and Eucalyptus plantation were stronger than those of tea plantation, loquat orchard and abandoned farmland. Water-stable aggregate stability was the highest in Chinese fir plantation, followed by eucalyptus plantations and tea plantations, and water-stable aggregate stability was the lowest in loquat orchards and abandoned farmland. Except for coarse dust, the other soil particle content of the same size had the different change under different land use patterns. The change of status of aggregate and degree of aggregation was opposite to the change of dispersive coefficient under different land use patterns. Water stability index and soil organic matter content in Chinese fir plantation, eucalyptus plantation and loquat orchard was higher than that of abandoned farmland and tea plantation. So, land use patterns of Chinese fir plantation and eucalyptus plantation was reasonable in study area.

Abstract: 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.