[Soil water environment of artificial vegetation in Jinshajiang dry-hot volley].

Jinshajiang dry-hot volley has the characteristics of extremely hot and dry climate due to its specific local climate, where universally exists moisture deficit and the problem of soil water environment of artificial vegetation becomes more serious than other arid and semi-arid areas. The environmental determination in the typical sector of dry-hot volley Yuanmou showed that the existed arboreous forests evidently showed the characteristics of soil drying. Soil was short of moisture for a long term. In November after the rain season was over, soil water content in two-meter-deep soil layer was only 15% (equal to 35% of field capacity). Later on, soil water content continued decreasing and reached the lowest point in May (9%), which was near to wilting moisture of trees (the wilting moisture of surface eroded dry red soil of Yuanmou was 9.0%). As a result, trees grew slowly. As for Radonaea wiscosa shrubbery, its soil water content at the same layer was relatively 42.68% higher than that of arboreous trees. The soil moisture of natural grass slope was evidently better than that of arboreous trees and shrubbery, and was 34.36% and 22.22% higher, respectively. This kind of soil drying problem didn't come into notice in the vegetation restoration of Jinshajiang dry-hot volley, which would greatly restrict the sustainable development of artificial vegetation.