Acta Agriculturae Zhejiangensis ›› 2025, Vol. 37 ›› Issue (4): 847-857.DOI: 10.3969/j.issn.1004-1524.20240254

• Plant Protection • Previous Articles     Next Articles

Exploring the degradation and soil enzyme impact of pyroxasulfone and its main metabolites in soils

DU Song1,2(), TANG Tao2, CHENG Xi2, ZHAO Xueping2, ZHANG Chunrong2, LIANG Xiaoyu3, WANG Meng3, ZHANG Zhen4, LI Yongcheng1, ZHANG Chenghui1,*()   

  1. 1. College of Food Science and Engineering, Hainan University, Haikou 570228, China
    2. Institute of Agro-Product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
    3. College of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
    4. Key Laboratory of Quality and Safety Control for Subtropical Fruit and Vegetable, Ministry of Agriculture and Rural Affairs, Analysis and Test Center, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China
  • Received:2024-03-19 Online:2025-04-25 Published:2025-05-09

Abstract:

Pyroxasulfone, a new isoxazole pre-emergence herbicide, is registered for use on wheat, but the risk of its main metabolites, M-1 and M-3, to the soil environment is not known. In this study, the effects of different physicochemical conditions on the elimination of pyroxasulfone and its major metabolites, as well as the effects of pyroxasulfone and its major metabolites on soil enzyme activities were investigated using three types of soils with different physicochemical properties, namely, black soil, brown soil, and red soil. The results showed that M-1 and M-3 were eliminated at lower rates than the parent in different soils, after 120 d of incubation in three soils, the elimination rates of pyroxasulfone ranged from 12.3% to 38.0%; those of M-1 ranged from 3.8% to 4.6%; and those of M-3 ranged from 4.6% to 21.0%. Pyroxasulfone is readily dissipated in soils with high pH value and high organic matter content (black soils), M-1 is readily dissipated in soils with high cation exchange (black soils), and M-3 is readily degraded in soils with low pH value and low organic matter content (red soils). Soil cation exchange and pH value were the main factors affecting the dissolution of M-1 and M-3. And both M-1 and M-3 gradually accumulated during the parent elimination process. The effect on soil enzyme activities was found that pyroxasulfone and its metabolites, M-1 and M-3, inhibited soil acid phosphatase, β-glucosidase, urease, and dehydrogenase activities, and the metabolites inhibited them more strongly than pyroxasulfone. Therefore, the ecological risks of pyroxasulfone and its metabolites need to be considered comprehensively when assessing the potential risk of pyroxasulfone to soil, so as to provide a scientific basis for the rational use of pesticides.

Key words: pyroxasulfone, metabolites, elimination dynamics, soil enzyme activity

CLC Number: