More than forty years of revegetation using mainly Artemisia ordosica, and Caragana korshinskii at Shapotou Desert Experimental
Research Station near Lanzhou has established a dwarfshrub and herbaceous cover on stabilized sand dunes. Situated in southeast Tengger desert at 1 330 m elevation, it has an average annual rainfall of 191 mm with 83% received from May to September. Precipitation, as the sole source of water replenishment in the semiarid area, plays a pertinent role in sustaining the desert ecosystem. The water
penetration experiment on soils of microbiotic crust, fine sandy loam and pure dune sand at different initial soil moisture content (θi) were conducted by the horizontal penetration equipment in the laboratory. The soil moisture distribution was tested by sampling core soil at an interval of 5 cm from the point of water entrance. The results indicated that, for the selected experimental soils, water penetration coefficient (λf) were decreased in response to an increased θi, respectively. The λf of sand was much more high as compared to that of microbiotic soil crust and sandy loam at every single θi. The sandy loam has a less sharp decline feature of λf with an increased θi, in comparing with that of microbiotic soil crust and dune sand. Due to the soil texture peculiarity, λf is 4 times in microbiotic soil crust than that in dune sand, in spite of initial soil moisture content. The microbiotic soil crust has a value of 1.5 times of average soil moisture content both along the soil profile and at a distance of 0～5 cm and 5～10 cm from the wetting front than that of dune sand. We may conclude that the microbiotic soil crust has a more hydrophilic property, which contributes a big majority proportion in retaining rainfall than dune sand does in Shapotou regions.