地表覆膜对季节性冻融土壤入渗规律的影响

该文以指导农田冬春灌溉为目的，利用双套环入渗仪积水入渗试验法，进行了季节性冻融期田间系列土壤入渗试验，分析了地表覆膜对冻融土壤入渗特性的影响。试验结果表明：地表覆膜具有明显的保温保墒作用，在地膜覆盖条件下，土壤冻结滞后，解冻过程提前，土壤含水率变化较小；冻结初、中期覆膜地的土壤入渗能力高于裸地，而冻结末期和消融期则表现出相反的规律；冻融期地膜覆盖使得土壤出现最小入渗能力的时间滞后于裸地近20 d。研究结果对于指导季节性冻融区冬春灌溉合理灌水技术参数的确定及高效利用土壤水资源具有重要的理论和实际意义。

Influence of plastic film mulching on infiltration into seasonal freezing-thawing soil

In order to guide farmland irrigation in winter and spring, a series of field infiltration tests during seasonal freezing-thawing period were conducted using two-ringer infiltration apparatus, and the effects of plastic film mulching on infiltration characteristics were analyzed. Results show that plastic film mulching on soil surface has obvious heat and soil moisture conservation effect; the soil covered with plastic film freezes late and thaws early, and soil water content has less change. In early and middle freezing period, the infiltration capacity of plastic film mulching plot is higher than that of bare plot, but it is in reverse case in the last freezing period and whole thawing period. During seasonal freezing-thawing period, the time that the minimum infiltration capacity of plastic film mulching plot appears, compared with the bare plot, is about 20 days later. The research results have practical and theoretical values for effective utilizing of soil water resources and reasonable guiding of irrigation in winter and spring in seasonal freezing-thawing regions.