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研究了加拿大南部冬小麦田在轮作、耕作和行距共同作用下的土壤温度动态。田间裂区试验主区为 3个轮作 (冬小麦连作、冬小麦 /油菜轮作和冬小麦 /夏休闲 ) ,副区包括两种耕作技术 (免耕和常规耕作 ) ,小裂区包括两种种植行距 (等行距和大小行 )。结果表明 ,免耕处理下秸秆覆盖有效地降低了冬季土壤的冻结深度。在 1993～ 1994年度 ,连作小麦免耕土壤的 -5℃等温线要比常规耕作浅 2 2 cm。免耕秸秆覆盖的温度效应在冬小麦连作和冬小麦 /油菜两种轮作上比在冬小麦 /夏休闲上更为明显。在冬小麦连作和冬小麦 /油菜轮作下 ,免耕土壤 2 .5 cm的春季温度连续 4个月显著低于常规耕作土壤。1994年 4月 8日 ,免耕和常规耕作农田 2 .5 cm处的温差在冬小麦连作处理上达到 4.1℃。对于冬小麦 /夏休闲处理 ,由于秸秆覆盖量较少 ,耕作措施对土壤温度的影响不太明显。在 1994年春季 ,大小行种植的土壤温度显著高于等行距种植的土壤温度。因此 ,免耕主要通过秸秆覆盖来改变土壤的温度状况。通过轮作、耕作和行距等措施 ,可以在一定程度上实现土壤温度的人为调节
Soil temperature dynamics in winter wheat fields in southern Canada under the combined action of rotation, tillage and spacing were studied. The main experimental plot in the field split-zone experiment consisted of three rotation (winter wheat continuous cropping, winter wheat / canola rotation and winter wheat / summer recreation). The sub-zone consisted of two tillage techniques (no-tillage and conventional tillage), the split zone consisted of two planting lines Line spacing and size line). The results showed that straw mulching without tillage effectively reduced the freezing depth of winter soil. In 1993-1994, the -5 ℃ isotherm of no-till wheat under continuous cropping was 22 cm lighter than that of conventional tillage. The temperature effect of no-tillage straw mulching was more obvious in winter wheat cropping and winter wheat / rapeseed rotation than in winter wheat / summer recreation. Under winter wheat cropping and winter wheat / canola rotation, the spring temperature of 2.5 cm in no-till soil was significantly lower than that of conventional tillage soil for 4 months. On April 8, 1994, the temperature difference at 2.5 cm between no-till and conventional farming reached 4.1 ° C on continuous cropping of winter wheat. For the winter wheat / summer leisure treatment, the effect of tillage measures on soil temperature is not obvious due to the small amount of straw mulching. In the spring of 1994, the temperature of soils planted in rows and columns was significantly higher than that of soils grown in equally spaced rows. Therefore, no-till mainly changes the temperature of the soil through straw mulch. By means of crop rotation, tillage and row spacing, artificial adjustment of soil temperature can be achieved to some extent