Elimination of herbicide residue by soil displacing plough in soybean fields

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 5.2% 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.