Instituto de Recursos Naturales y Agrobiologı́a de Sevilla (IRNAS), CSIC , Avenida Reina Mercedes 10, 41012 Sevilla, Spain.
Agricultural Research Service, U.S. Department of Agriculture , 439 Borlaug Hall, 1991 Upper Buford Circle, St. Paul, Minnesota 55108, United States.
J Agric Food Chem. 2017 Apr 19;65(15):3109-3117. doi: 10.1021/acs.jafc.7b00458. Epub 2017 Apr 5.
Biochar (BC), solid biomass subjected to pyrolysis, can alter the fate of pesticides in soil. We investigated the effect of soil amendment with several biochars on the efficacy of two herbicides, clomazone (CMZ) and bispyribac sodium (BYP). To this aim, we evaluated CMZ and BYP sorption, persistence, and leaching in biochar-amended soil. Sorption of CMZ and BYP was greater in soil amended with BC produced at high temperature (700 °C). Significant sorption of the neutral CMZ herbicide also occurred in amended soil with BC prepared at low temperature (350 and 500 °C). For both herbicides, desorption possessed higher hysteretic behavior in soil amended with BC made at 700 °C (pyrolysis temperature). Dissipation of CMZ was enhanced after addition of BCs to soil, but no correlation between persistence and sorption was observed. Persistence of BYP was up to 3 times greater when BC made at 700 °C was added to soil. All BCs suppressed the leaching of CMZ and BYP as compared to the unamended soil. Amendment with 700 °C BC inhibited the action of CMZ against weeds, but 350 and 500 °C BCs had no such effect when added to soil. BYP activity was similar to that exhibited by unamended soil after the addition of 700 °C BC. From these results, biochar amendments can be a successful strategy to reduce the environmental impact of CMZ and BYP in soil. However, the phytotoxicity of soil-applied herbicides will depend on BC sorption characteristics and the pesticide's chemical properties, as well as the pesticide application timing (e.g., pre- or postemergence). According to our results, proper biochar screening with intended pesticides in light of the application mode (pre- or postemergence) is required prior to use to ensure adequate efficacy.
生物炭（BC）是经过热解的固体生物质，可以改变土壤中农药的命运。我们研究了几种生物炭对两种除草剂氯唑草酮（CMZ）和双丙环虫酯（BYP）功效的影响。为此，我们评估了生物炭改良土壤中 CMZ 和 BYP 的吸附、持久性和淋溶。在高温（700°C）下制备的生物炭改良土壤中，CMZ 和 BYP 的吸附作用更强。在低温（350°C 和 500°C）下制备的生物炭改良土壤中，中性除草剂 CMZ 也表现出显著的吸附作用。对于这两种除草剂，在 700°C 下制备的生物炭改良土壤中解吸具有更高的滞后行为（热解温度）。在向土壤中添加生物炭后，CMZ 的消解得到增强，但持久性与吸附之间没有相关性。当向土壤中添加 700°C 下制备的生物炭时，BYP 的持久性增加了 3 倍。与未改良的土壤相比，所有生物炭都抑制了 CMZ 和 BYP 的淋溶。与未改良的土壤相比，添加 700°C 生物炭抑制了 CMZ 对杂草的作用，但添加 350°C 和 500°C 生物炭对土壤则没有这种作用。添加 700°C 生物炭后，BYP 的活性与未改良的土壤相似。根据这些结果，生物炭改良可以是减少土壤中 CMZ 和 BYP 环境影响的一种成功策略。然而，土壤施用药剂的植物毒性将取决于生物炭的吸附特性和农药的化学性质，以及农药的施用时间（例如，出苗前或出苗后）。根据我们的结果，在使用之前，需要根据应用模式（出苗前或出苗后）对拟用农药进行适当的生物炭筛选，以确保足够的功效。
