土层置换犁消除豆田残留除草剂药害的效果

Elimination of herbicide residue by soil displacing plough in soybean fields

为探索消除豆田残留除草剂对后作药害的新途径,本研究采用生物鉴定的方法,以甜菜为指示植物查明了豆田残留除草剂主要分布在0～10cm土层中,向下层逐渐减少,20cm以下土层为安全土层。自主设计的土层置换犁实现了将0～20cm土层和20～40cm土层位置转换,即所谓的土层置换。应用该犁在有残留除草剂污染的豆茬上实施土层置换改土作业后,连续2年调查作物产量结果显示,土层置换区比对照区甜菜、马铃薯等作物长势好、杂草数量少;改土后种植甜菜,第1年、第2年分别比未改土的对照增产468.9%和805.7%;种植马铃薯分别增产177.1%和31.0%;种植玉米(第2年)增产2.0%。种植连作大豆(第2年)增产6.5%。同时在未受到残留除草剂污染的土壤上实施土层置换作业后,第1年种植马铃薯和甜菜分别比对照减产3.1%和5.6%、第2年种植马铃薯和玉米,分别增产27.0%和5.2%。研究结果可为修复残留除草剂污染土壤、消除作物连作障碍和促进种植业结构提供技术支撑。

In order to explore a new method to eliminate phytotoxicity of herbicide residue in soil, sugar beet was used as indictor plant to identify the residual herbicide which was measured by biological identification method. The residual herbicide was mainly distributed in soil layers of 0-10 cm and gradually reduced from 10 cm to 20 cm with the secure layer below 20 cm in a soybean field. The layer of 0-20 cm and 20-40 cm was switched by soil displacing plough of independent design, so called soil displacement. After soil displacement was carried out in a soybean field with herbicide residue by two years, the growth of sugar beet and potato became much better, while few weeds could survive in the field compared to the control. Compared to the control, the yield of sugar beet increased by 468.9% and 805.7%, and yield of potato increased respectively by 31.0% and 177.1% in the first year and the next year, respectively. Compared to the control, the yield of maize and soybean were increased by 2.0% and 6.5% in the second year, respectively. At the same time, this plough was also applied in a soybean field with no soil pollution by herbicide residue. Compared to the control, the yield of potato and sugar beet were decreased respectively by 3.1% and 5.6% in the first year, but the yield of corn and potato increased respectively by 5.12% and 27.0% in the next year. The research can give technological support to renovate the soil with herbicide residues, eliminate the barrier of crop rotation and promote plant structure.