焉耆县滴灌条件下土壤水热盐的动态变化特征

为了揭示焉耆县良种场的土壤水热盐动态变化，对有膜覆盖和无膜覆盖条件下各土壤层进行水热盐的系统观测和单因素方差分析及相关性分析。结果表明：（1）土壤温度的日变化呈现先降低后升高再降低的趋势，有膜各层土壤温度高于相对应的无膜各层土壤温度，各层土壤温度和大气温度变化趋势一致。（2）有膜各层土壤盐分要高于相对应的无膜各层土壤盐分，表层土壤水分小于底层，有膜10～20 cm土壤水分含量比较低，无膜10～50 cm土壤水含量比较接近；滴灌后，土壤水分和盐分经历快速下降和缓慢下降两个过程。由于文献对于有膜覆盖与无膜覆盖条件下土壤水热盐变化的研究相对较少，文章通过研究焉耆县农田生育期有膜和无膜条件下土壤水热盐的变化特征，为研究区土壤盐渍化的防治提供科学依据。

Dynamic characteristics of soil water,heat and salt under drip irrigation in Yanqi County

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.