秸秆覆盖厚度对冻融期土壤温度的影响

Effects of Corn Mulch Thickness on Soil Temperature during Freezing-thawing Period

基于冻融期玉米秸秆覆盖厚度为5,10,15,20,30cm及无覆盖6种不同地表处理条件下农田土壤温度的测定,分析了冻融期秸秆覆盖对土壤温度的影响及秸秆覆盖厚度与土壤温度变化之间的关系。结果表明,冻融期秸秆覆盖改变了土壤温度分布与变化特征。随着秸秆覆盖厚度从5cm增加到30cm,各土层土壤温度在冻融期的变幅以及由气温突然变化引起的土壤温度波动幅度减小,土壤剖面最低温度值升高,土壤温度响应气温变化的滞后效应增强,土壤温度变化速率线性降低。秸秆覆盖厚度对土壤温度的影响作用随着土壤深度的增加逐渐减弱,地表下60cm处,5种秸秆覆盖处理的土壤温度分布没有明显差异。研究成果可为季节性冻土分布区农田实施秸秆覆盖措施提供参考依据。

Based on the soil temperature measurement of bare plot and corn straw mulch plots with mulch thickness of 5, 10, 15, 20 and 30 cm during freezing-thawing period, this paper ana- lyzed the influence of corn straw mulch on soil temperature and the relationship between straw mulch thickness and soil temperature change. The results show that the corn straw mulch altered the soil temperature distribution. As the straw mulch thickness increased from 5 cm to 30 cm, the temperature variation of each soil layer and the temperature fluctuation induced by abrupt change of air temperature declined, the lowest soil profile temperature dropped, the lag effect of soil temperature in response to the air temperature variation increased, and the rate of soil tem- perature change slowed down. With the increase of soil depth, the effects of straw mulch thick- ness on soil temperature variation and distribution grew weaker gradually. At the depth of 60 cm benea ence. glons. th soil surface, the soil temperatures of 5 straw mulched plots showed no obvious differ These results provide a basis for applying straw mulch in seasonal freezing-thawing re