There are some critical relationships between soil surface temperature and soil evaporation, and the texture of soil affect those two variables.【Objective】This paper amis to explore the effect of soil temperature changes on soil evaporation in different textures.【Method】Five types of soil were produced by two kinds of soil whose texture were silty loam and sand with different proportion in this experiment. Each mixed soil was tested in situation of sufficient soil moisture and situation of non-sufficient soil moisture, the evaporation, soil surface temperature under those two kinds of situation and soil texture were measured. And the relationship between relative evaporation(RE) and relative difference of soil surface temperature(RT) in different textures were studied.【Result】①The relative difference of soil surface temperature(RT) increases with the procession of evaporation until the evaporation going to water vapor diffusion stage, and RT would be steady after that;②In stage of water vapor diffusion, the relative difference of soil surface temperature(RT) reduced with the increasing of soil sand proportion;③ When soil texture was the same, the relative evaporation(RE) reduced in a quadric relationship with the relative difference of soil surface temperature(RT);④The relative evaporation(RE) reduces with the increasing of sand percentage of soil when RT was a constant.【Conclusion】The difference of sand proportion in soil makes the difference of soil pores and heat capacity, which leads to the regularity of soil temperature and evaporation during evaporation, and the quadric relationship between relative evaporation and relative difference of soil surface temperature.
Journal of Irrigation and Drainage
soil surface temperature