| Moisture in soil is only water source for vegetation, due to seasonal distribution of precipitation, air temperature, ground temperature and influence of other factors, soil moisture used by efficiency of vegetation gives rise of apparent change. So in different region, distribution pattern and law of variation of soil moisture is different, pattern of moisture and way of consume of different vegetation utilization is different. The research carry on elementary study for dynamic of soil moisture, physiologic trait and consumed water of in sand-land of HeDong NingXia, the result :①proportionality of evaporation of soil and water with percent moisture content of soil has certainly relation, the related formula is: y = -4E + 07x4 +2E+ 07x3 -5E + 06x2 + 440762x -15830 The related coefficient R=0.8329, result shows proportionality of evaporation of soil and water with percent moisture content of soil has minus relation.②daily variation of transpiration rate of Caragana korshinskiiin may divide singly top and double top, daily variation of transpiration rate of A.dasystachys Anspiration has merely double top. ③water potential of leaf of A.dasystachys Anspiration is less than Caragana korshinskiiin in wholly day. It show moisture condition of Caragana korshinskiiin is more than A.dasystachys Anspiration, and deal with the ability of drought environment is stronger than A.dasystachys Anspiration. ④Congress of soil moisture and transpiration rate of the Caragana korshinskiiin about 15cm, 60cm is: Tr = -537.158C15+33.125C(60) +4175.682 R = 0.719; Congress of soil moisture and transpiration rate of the A.dasystachys Anspiration. about 30cm, 60cm is:Tr =940.982C30 +182.085C60 - 2836.798 R = 0.884.⑤transpiration rate and water potential of leaf of A.dasystachys Anspiration and Caragana korshinskiiin may be described by following formula: y=ax + b the result show that transpiration rate of A.dasystachys Anspiration and Caragana korshinskiiin can increase when water potential of leaf decreases.⑥regression equation of transpiration rate of Caragana korshinskiiin with air humidity, ground temperature of 0cm and 5cm, air temperature is:Tr = -4.809M + 29.302G0 - 4.128G5 - 44.1331+1095.743, R = 0.926. regression equation of transpiration rate of A.dasystachys Anspiration with air humidity, ground temperature of 0cm and 20cm, air temperature is:Tr = 4.74M + 49.509G0 + 34.47G20 - 77.045T - 509.236 R = 0.975. ⑦In different hydrologic year, evapotranspiration in sample plot of Caragana korshinskiiin differ greatly, but proportionality of evaporation and precipitation is nearly equally . In sample plot of A.dasystachys Anspiration ,the evapotranspiration is more apparent than sample plot of Caragana korshinskiiin, proportionality of evaporation and precipitation is greatly. So the more precipitation does in the region , the more soil evaporation and transpiration of plant is more much, evapotranspiration in year of abundant precipitation is great than level year.
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