Correlation analysis of soil physicochemical properties under different soil and water conservation biological measures in Three Gorges Reservoir Region

In order to prevent soil and water loss and improve the soil properties in Three Gorges Reservoir Region, the effects of different biological measures on soil physicochemical properties under different soil and water conservation biological measures were comprehensively evaluated by grey correlation coefficient analysis to select better measures. The result showed that all different biological measures improved soil physicochemical property compared with control——bare land although the effects varied with measures. Under different biological measures, the tested indices including soil bulk density, total porosity, soil organic matter, total nitrogen, total phosphorus, total potassium and soil C/N were the significantly different (P<0.05) or extremely significantly different (P<0.01). The soil total porosity, organic matter, total nitrogen, total phosphorus, total potassium, alkaline hydrolysis nitrogen, available potassium and soil C/N were the highest under treatment with Koelreuteria bipinnata+Sophora xanthantha. The improved effects of soil physicochemical properties decreased in the following order: K. bipinnata+S. xanthantha>hedgerows>closed forest>natural restoration>economic forest>traditional planting>bare land. The measure with K. bipinnata+S. xanthantha had great effects for preventing soil and water loss which could be applied further. These results had an important significance for ecological civilization construction and the management of soil and water loss in Three Gorges Reservoir Region