地表覆盖对季节性冻融土壤温度影响研究

基于季节性冻土分布区冻融期间土壤温度的田间试验,研究了地膜覆盖、地膜与秸秆双重覆盖对冻融土壤剖面温度的影响。结果表明:地膜覆盖对试验土层有明显的增温效应,而地膜、秸秆双重覆盖对土壤增温的影响只限于耕作层内;越冬期试验土层范围内,各处理地块的地温均经历降低、趋于稳定、升高的过程;地膜、秸秆覆盖可平抑土壤温度变化,明显缩小温差;在冻结阶段和融化阶段,三种处理地块40~100 cm深度处地温降低和升高的幅度随深度的加大而减小。研究结果对于改善季节性冻土区土壤热状况,指导农业生产具有实际意义。

The Effect of Different Surface Mulchings on Soil Temperature During Seasonal Freezing-thawing Period

Based on the experimental data of soil temperature in the profiles during freezing-thawing period,the effects of plastic mulching and plastic film plus straw mulching on soil temperature are analyzed.The results indicate that there is an apparent effect of increasing temperature when the soil surface is covered with plastic film in seasonal freezing-thawing areas,however, plastic film plus straw mulchings merely raises the temperature within plough layer.Soil temperatures of three treatment plots go through the process of depressing-stabilizing-elevating within the experimental soil layers in winter and spring.Plastic film plus straw mulching can also stabilize the changes of soil temperature,and reduce the difference in temperature obviously.The elevated and depressed amplitude of soil temperatures in soil layer(40 to 100cm) decreases along with the increasing depth whether freezing and thawing stages or not.The results are of practical meaning to improve soil thermal regime and guide agricultural production in seasonal frozen districts.