State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; Hebei Key Laboratory of Crop Stress Biology (in Preparation), Hebei Normal University of Science and Technology, Qinhuangdao 066004, China.
Ecotoxicol Environ Saf. 2024 Oct 15;285:117141. doi: 10.1016/j.ecoenv.2024.117141. Epub 2024 Oct 4.
Pyroxasulfone is a relatively new herbicide that is sprayed on soils to control grassy weeds and some broadleaf weeds during the cultivation of agronomic crops. However, information regarding its environmental risks to soil ecosystems is currently limited. Here, the response of soil characteristics and soil bacterial communities to pyroxasulfone exposure were evaluated. The rate of pyroxasulfone degradation in soil decreased with increasing herbicide concentration, and its half-life at doses of 0.12 (the recommended field rate), 1.2 and 12 mg kg was estimated to be 15.75 d, 39.46 d and 78.08 d, respectively. Soil pH markedly increased after pyroxasulfone treatment. Pyroxasulfone significantly inhibited urease activity but had a small effect on soil sucrase activity. In the late stages of degradation, the abundance of bacteria clearly decreased in soils treated with pyroxasulfone at doses of 1.2 and 12 mg kg. Compared with the control group, a distinct decrease in bacterial network complexity was observed at a pyroxasulfone dose of 0.12 mg kg, while the opposite phenomenon was observed at a pyroxasulfone dose of 12 mg kg. The copy numbers of the AOA amoA and AOB amoA genes exposed to 10- and 100-fold the recommended rates of pyroxasulfone were significantly lower than those in soils without pyroxasulfone residue at 25 and 60 days after treatment. In summary, pyroxasulfone at the recommended rate had a slight effect on soil enzymes, the bacterial community and soil nitrification; however, the potential adverse impacts of pyroxasulfone at higher concentrations on these soil factors deserve further attention.
吡唑草酮是一种相对较新的除草剂，在农业作物种植期间，它被喷洒在土壤上以控制杂草和一些阔叶杂草。然而，关于其对土壤生态系统的环境风险的信息目前有限。在这里，评估了土壤特性和土壤细菌群落对吡唑草酮暴露的反应。土壤中吡唑草酮的降解速率随除草剂浓度的增加而降低，其在 0.12（推荐田间用量）、1.2 和 12mgkg 的半衰期估计分别为 15.75、39.46 和 78.08d。吡唑草酮处理后土壤 pH 值明显升高。吡唑草酮显著抑制脲酶活性，但对土壤蔗糖酶活性影响较小。在降解后期，吡唑草酮用量为 1.2 和 12mgkg 的土壤中细菌丰度明显下降。与对照组相比，在吡唑草酮剂量为 0.12mgkg 时，细菌网络复杂性明显降低，而在吡唑草酮剂量为 12mgkg 时则相反。暴露于吡唑草酮推荐剂量的 10-和 100 倍时，AOA amoA 和 AOB amoA 基因的拷贝数明显低于处理后 25 和 60 天无吡唑草酮残留的土壤。总之，推荐剂量的吡唑草酮对土壤酶、细菌群落和土壤硝化作用有轻微影响；然而，吡唑草酮在更高浓度下对这些土壤因素的潜在不利影响值得进一步关注。
