不同初始盐分浓度下土壤盐结皮的形成过程及其对蒸发的影响机理  

Formation process of soil salt crust and its influence mechanism on evaporation under different initial salt concentrations

作　　者：唐洋 李新虎[1,2,3] 郭敏 王弘超 TANG Yang;LI Xinhu;GUO Min;WANG Hongchao(Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,Xinjiang,China;National Field Scientific Observation and Research Station of Aksu Oasis Farmland Ecosystem,Aksu 843017,Xinjiang,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院新疆生态与地理研究所,新疆乌鲁木齐830011 [2]新疆阿克苏绿洲农田生态系统国家野外科学观测研究站,新疆阿克苏843017 [3]中国科学院大学,北京100049

出　　处：《干旱区地理》2022年第4期1137-1145,共9页Arid Land Geography

基　　金：由西部青年学者项目(2020-XBQNXZ-012);国家自然科学基金项目(41977013)资助。

摘　　要：土壤盐结皮对土壤水文过程具有重要影响,初始盐分浓度(Initial salt concentration,ISC)的差异会对盐结皮的形成过程产生不同程度的影响,从而导致土壤蒸发的差异。但目前不同ISC下盐结皮形成过程对土壤蒸发的影响机理尚不明确。因此,通过试验模拟与理论分析相结合,动态监测及分析不同ISC下砂土的盐结皮形成、蒸发、土壤表面温度动态变化过程,以期阐明不同ISC下盐结皮形成过程及其对土壤蒸发的影响机理。结果表明:ISC越高,盐结皮在土壤表面出现的时间越早,覆盖率越大,且在同样光照强度和光照时间条件下土表温度增幅越小,蒸发量也越小;对数函数能较好地拟合不同ISC与累积蒸发量之间的关系(R^(2)>0.90);随着ISC的增加,盐结皮对土壤蒸发抑制效率从24.14%(10 g·L^(-1))增大到71.99%(250 g·L^(-1))。ISC会显著影响盐结皮形成的过程,并通过影响土表温度的变化进而导致土壤蒸发出现巨大差异。The effects of soil salt crusts on the soil hydrological process have gained considerable attention.Soil salt crusts have an important effect on the soil hydrological process.The formation process of salt crusts treated with different initial salt concentrations is substantially different,resulting in the difference of soil evaporation.However,the influence of salt crust formation on soil evaporation under different initial salt concentrations is not well understood.Therefore,this study theoretically and experimentally monitored and analyzed the changes in salt crust formation,evaporation,and soil surface temperature of sandy soil under irrigation water treatment with different initial salt concentrations to clarify the soil salt crust formation process of irrigation water treatment with different initial salt concentrations and its influence mechanism on soil evaporation.Results show that with the increase in initial salt concentrations,the salt crust quickly formed on the soil surface,the coverage of salt crust on the soil surface increased,the increase in the soil surface temperature slowed,and the evaporation decreased under the same light intensity and exposure time.The relationship between the initial salt concentrations and cumulative evaporation could be expressed by a logarithmic function(R^(2)>0.90).With the increase in the initial salt concentrations,the inhibition efficiency of salt crust on soil evaporation increased from 24.14%(10 g·L^(−1))to 71.99%(250 g·L^(−1)).The initial salt concentrations could significantly affect the formation process of salt crusts,thereby leading to a considerable difference in soil evaporation by changing the soil surface temperature.

关 键 词：初始盐分浓度 盐结皮 形成发育 土表温度 土壤蒸发 

分 类 号：S156.41[农业科学—土壤学]