【目的】研究东北冷凉区免耕对土壤性状、作物产量的影响及其水土保持作用。【方法】利用平地和坡地9年长期定位田间试验,设置免耕和旋耕处理,系统监测土壤性状和作物产量。【结果】与传统旋耕相比,免耕下耕层土壤含水量提高3—5个百分点,110 cm土层储水量增加;10 cm处土壤温度降低2.1℃;0—15 cm土层有机质含量增加11%;土壤动物多样性增加;地表径流和土壤流失量分别减少90%和98%以上;玉米减产20%以上,大豆却增产10%左右;免耕在坡地上的效果好于平地。【结论】免耕对退化黑土恢复和水土保持作用显著,但冷凉区作物对免耕反应不同:大豆增产,玉米减产。因此,免耕适宜于大豆和坡耕地。
[Objective] The effects of no-tillage (NT) on studied in the north cool area of Northeast China. [Method] soil properties, crop yields, and soil and water conservations were Two long-term filed experiments were established to compare the performance of two systems NT and conventional rotary tillage (CRT) in a flat field and a slope land, respectively. Soil properties and crop yield were measured and soil runoff was monitored continuously. [Result] Compared to CRT, soil water content under NT in the plowed layer was increased by 3 to 5 percentage points, which led to increasing soil water storage in the 110 cm layer. At the depth of 10 cm, soil temperature under NT was 2.1 ℃ lower than that under CRT. In the 0-15 cm soil layer, soil organic matter content under NT was 11% higher than that under CRT, which resulted in the increase of the diversity of soil animal community. With the adoption of NT, soil surface runoff and soil loss were decreased by 90% and 98%, respectively. Finally, compared to the CRT system, corn yield under NT was decreased by more than 20%, while soybean yield under NT was increased by approximately 10%. In addition, these benefits of NT were more significant in the slope land than those in the fiat field. [Conclusion] NT displayed a significant role in soil and water conservation in the degraded land. On the other hand, NT decreased corn yield but increased soybean yield. It was concluded that NT is a useful practice for soybean and sloping farmland in the north cool region of Northeast China.