Abstract: The effects of film mulching of millet on soil water content were studied in semi-arid areas in loess plateau of South Ningxia. Different mulching methods including water micro-collecting farming(WF), water micro-colleting farming in winter fallow(WW)，hole seeding on film(HF), hole seeding on film in winter fallow(HW) were compared to determine the effects of mulching methods on soil water collecting and conservation during millet growth periods of 2003-2004, the variation tendency of water after rainfall, output of millet and water use efficiency(WUE). The experimental results in successive two years indicated that water micro-collecting farming had the function of better collecting water after rainfall, and side infiltrated water was stored under its ridge and the top layer 0-40 cm soil water changes were greater. WF had obvious water collection and preservation of soil moisture f. WF effectively improved the water supply capacity by about 19.05% in the end of growth seasons. The storage of HW and WW increased by 24.9 and 7.1 mm compared with CK, and output of yield were obviously increased. Film mulching increased the yield of millet and enhanced water use efficiency (WUE). During different growth periods, WF had better water storage, the lower amount of water consumption, and demonstrated better social and ecological benefits.

Key words: Millet, Dynamic change of soil moisture, Film mulching, Water micro-collecting farming