少免耕模式对冬小麦生长发育及产量性状的影响

The Effect of Minimum Tillage and No-tillage on Growth and Yield of Winter Wheat

通过田间试验研究了华北平原山前平原区不同耕作方式下，冬小麦的生长发育进程的变化及对产量的影响。根据冬小麦播种前的土壤耕作方式的不同，设深耕处理、少耕处理和免耕处理3类、6个处理。研究结果表明：耕作方式明显影响小麦的出苗率，传统翻耕处理出苗率比免耕高出27．1％～46．2％。由于秸秆的覆盖，免耕处理小麦返青期低温偏低，导致生育期推迟7～10d，后期作物生长受到明显影响，是造成免耕处理减产的重要原因之一。另外，由于免耕处理蒸发较小和小麦根系不发达，NO3^--N淋失到土壤剖面的100cm以下，不仅使氮肥利用率低，也是造成免耕减产原因之一。

The growth and yield of winter wheat were studied on field experiments under different tillage models in North China Plain. Based on tillage models, 6 treatments were set including plough, rotate and zero tillage. The results showed that the tillage fashions greatly affected the ratio of leaf emergence in wheat. The ratio leaf emergence in plough was 27.1% -46.2% higher than that in zero tillage. Because of mulching the soil temperature under zero tillage in turning green stage was lower than that of other treatments, which led to delay 7 - 10 days of wheat growing season and affect grain filling. Owing to less water evaporation and undeveloped wheat roots under zero tillage, it was easy to leaching of nitrate nitrogen below the soil depth of 100 cm. As a result, both the ratio of nitrogen utilization and the wheat yield decreased.