Abstract: Field monitoring results of wasteland soil water content of during growing season of seven years in Zhuanyaogou valley of northwestern Shanxi Province,and the results showed that the seasonal dynamics of the soil water was controlled by annual precipitation and its distribution.The seasonal dynamics of soil water in a normal rainfall year could be divided into three stages,i.e., consumption stage from late spring to early summer,storage stage from late summer to early autumn,and second consumption stage from late autumn to early winter. The relationship equation between soil water content and measuring number was linear (1988, 1990), exponent (1992, 1995) and parabola curve (1993). The vertical profiles of soil water in the wasteland in different rainfall year were different,and the soil water content increased with increasing depth . The equations between soil water content and soil depth in all years were cubic. Taking150cm as a boundary, the ratio of soil water content in lower layers to upper layers was larger than1, and the variance coefficient of soil water decreased with increasing depth. The soil water profile in0～300cm depth for seven year's average could be divided into three layers,i.e., active layer (above 200cm), transitive layer (between200～250cm) and stable layer (below 250cm), and the depth of each layer varied with the annual precipitation and its distribution. The ANOVA result of soil water content in extremely high rainfall showed a great difference with that in other years. The difference between soil water content in wasteland and in Caragana korshinskii plantation was significant, but was not different from that in Populus hopeiensis and Populus simonii plantation respectively. The quantitative analysis methods used in this paper facilitated the comparison of soil moisture in different region and in different vegetation.

Key words: Wasteland, Soil moisture, Fixed field monitoring, Spatial and temporal change