Effects of interplanting Vigna sinensis on soil water stable aggregate of Citrus reticulata orchard in purplish soil erosion region

It is common issues that developing of orchard in mountain easily leads to the destruction of soil structure and fertility in purple soil area. In this study, we analyze the effect of interplanting Vigna sinensis on the soil fertility and water stable aggregate of citrus orchard in purple soil region. The results indicated that interplanting V. sinensis on citrus orchard was conductive to the improvement of soil fertility, significantly (P<0.05) increased by 63.64% of total nitrogen, 20.90% of total phosphours, 93.43% of organic matters and 166.57% of available K compared to clean tillage, respectively. Meanwhile, interplanting V. sinensis on citrus orchard was benefit to the improvement of soil structure and stability of water stable aggregates, significantly increasing proportion of >5 mm and 2~5 mm water stable aggregate. 53.61% of soil water stable aggregates of citrus orchard interpreted by V. sinensis were >0.25 mm of size compared to clean tillage. Ratio of water stable aggregate (R0.25) and mean weight diameter (MWD) of interplanting V. sinensis treatment was significant higher of 25.22% and 35.90% than clean tillage treatment, respectively, however fractal dimension was lower of 5.17% than that. Finally, it was concluded that interplanting V. sinensis on citrus orchard increased soil fertility and soil structure in purple soil region, and it is a sustainable agricultural mode.