北方农牧交错带免耕对农田耕层土壤温度的影响

针对北方农牧交错带部分地区免耕措施生态效益好但作物产量有所下降的现状，为了找出影响作物生长的因素，对比分析了免耕和翻耕两种耕作方式下耕层土壤温度的变化。结果表明：免耕地升温和降温都比较缓慢且幅度小，翻耕地土壤温度在日间总体高于免耕地。在垂直方向上，土壤温度随土层深度降低，但一天中不同时刻的表现差异显著。土壤温度变化与当时气温呈正相关关系, 相关系数大于0.5。与免耕地相比，翻耕地气温与土壤温度的直线回归关系更显著。受土壤温度等物理性状的影响，免耕地作物生物量及产量明显不如翻耕地。因此，北方农牧交错带要通过农艺措施改善土壤物理结构，提高免耕农田作物产量。

Impacts of no-tillage on soil temperature of field in Ecotone of North China

Based on the better ecological effect but lower crop yield under no-tillage in Ecotone of north China, the changes of soil temperature under no-tillage and plow tillage were contrastively analyzed to find out the factors that affect the crop growth. Results show that the change of soil temperature is slower and less under no-tillage than that under plow tillage. In daytime, the soil temperature is higher under plow tillage than that under no tillage. The soil temperature in vertical section descends with the soil depth. The change trend within one day is significant. There exists positive correlativity between soil temperature and air temperature, and the correlation coefficient is over 0.5. The regressive relationship is more significant under plow tillage than that under no-tillage. Effected by soil temperature and the other physical properties, the biomass and yield are less under no-tillage than that under plow tillage. Therefore, soil physical properties should be ameliorated by the agricultural measurement to improve the crop yield in Ectone of North China.