Abstract: To study the dynamic characteristics of water,heat,and salinity in the soil column in Yanqi County, Xinjiang,China,we installed the EM50 instrument to measure temporal soil water,temperature,and salinity variations under both“with a film”and“without a film”coverage,and study their dynamics through the single factor analysis of variance and correlation analysis,for the period from July to September,2016,and the effect of irrigation on the water and salinity. The results show as follows: (1)the diurnal variation of soil temperature behaves like a cosine function. The top layer reached the highest temperature earlier than the bottom layer for both“with a film”and“without a film”setup,soil temperature for“with a film”at each layer is higher than the corresponding layers for“without a film”. Before flowering,the film had a significant positive influence on soil temperature. The variation trends of soil temperature and atmospheric temperature at different layers were consistent,and the atmospheric temperature and soil temperature reached the maximum in July 30^th,followed by a declining trend. (2)For both“with a film”and“without a film”setups,the soil salinity at 0-50 cm had a sine pattern,with higher variations in surface layer than bottom layer,in July,and average soil salinity was less in the surface layer than in the bottom layer; however in August,average soil salinity was larger at the surface than the bottom under “with a film”. (3)Similarly,soil moisture resembled a cosine pattern for both“with a film”and“without a film”,and soil moisture at the surface was less than the bottom. For“with a film”soil water was highest at 10-20 cm,while it was highest at 10-50 cm for“without a film”. At the end of drip irrigation,soil moisture and salinity experienced two rapid processes,i.e.,a rapid decline in the first 4 days,and a slow decline of from 5^th to 11^th days. Previous studies mainly focused on soil freeze-thaw cycles,different irrigation methods,irrigation water quality, water and salt changes,and there is not much comparative research on soil water,heat,and salinity under both “with a film”and“without a film”setups. The characteristics of soil water,heat,and salinity were studied under the condition of“with a film”and“without a film”in the growth period of farmland in Yanqi county. This is to provide a scientific basis for the prevention and treatment of soil salinization in the study area.

Key words: Yanqi, dynamics of water salt and temperature, with a film and without a film, drip irrigation