Abstract:In this study, three land use types (flat field farmland, shady slope terrace and sunny slope plantation) of Jiaxinzhuang Formation in the loess region of southern Ningxia were selected. Soil water content (SMC) was observed by soil drill in the growing season of 2021. At the same time, meteorological data were monitored by an automatic weather station. The spatio-temporal variation characteristics of SMC under the influence of land use, slope position and crop species were analyzed. The results showed that the order of SMC of the three land use types was flat field farmland (16.32%)>shady slope terrace (12.66%)>sunny slope plantation (10.82%). With the advance of the study period, SMC decreased first and then increased. There was excellent temporal synergy between SMC and precipitation. Temperature, solar radiation and saturation vapor pressure deficit were significantly related to the SMC of sunny slope plantations. With the increase of soil depth, SMC increased in flat field farmland, decreased in shady slope terrace, first decreased and then increased in sunny slope plantation. The variation coefficient of SMC in the 0—100 cm soil layer was greater than that in the 100—200 cm soil layer. Seasonal variation of SMC were divided into a relatively stable period (April-May), regression period (June-August) and recovery period (September-October). The change of SMC in different soil layers was divided into the active layer (0—40 cm), the relatively active layer (40—140 cm) and the relatively stable layer (140—200 cm). The replenishment time of soil moisture lagged behind precipitation, and the replenishment of lower soil moisture lagged behind that of upper soil. SMC of shady slope terrace and sunny slope plantation decreased first and then increased with the decreasing of slope position, and the minimum values were at the upper and middle-down slope position, respectively. Land use, slope position, crop species and meteorological elements were all factors that affected SMC. In terms of the variation degree of SMC, the effect of each factor on SMC followed the order of meteorological>land use>slope position>crop species. The results of this study were conducive to guiding the vegetation reconstruction and ecological industry development in semi-arid loess area, and determining the reasonable vegetation allocation under different site environments.