Study on Soil Physical and Nutrients Properties of Different Slope Aspects and Positions in Eroded Loess Hilly Region

To find soil physical and chemical properties response to re-vegetation,the purpose of this study was to investigate soil water content,bulk density and related physical characters and soil nutrients of different position in sunny slope and shady slope in eroded hilly-gully loess region.The result showed that soil water content increased as the distance from the top of the slope increased and soil water content in the shady slope higher than that of the sunny slope because of the evaporation in the shady slope was less,but bulk density showed the opposity regulation.Furthermore,bulk density,non-capillary porocity decreased and porocity ratio,capillary porocity increased as the distance from the top of the slope increased on the same slope aspect,bulk density increased with the soil depth in the sunny slope,however,there was little change of bulk density in the shady slope.It was concluded that the soil properties in the shady slope was better than that of the sunny slope,it was more advantage to the vegetation grows.Meanwhile,soil total nitrogen in the shady slope was higher than that of the sunny slope and decreased with depth.Soil total nitrogen and soil organic matter accumulated in the middle and down slope.Available potassium changed less and its quantity in the shady slope was more than in the sunny slope.The soil nutrients were higher in the upper layer of the soil while soil bulk density very significant negative correlation with the porocity ratio,capillary porocity,capillary moisture capacity and soil organic matter,but significant positive correlation with non-capillary porocity and soil water content of the upper layer.There existed very significant positive correlation with soil organic matter and total nitrogen and available potassium.The results of this study recommened that considered more on physical and chemical properties of the slope soil when restoration on the slope,meanwhile reasonable used and exploited land resources to enhanced the vegetation rehabilitation.