Future Industries Institute, University of South Australia, Mawson Lakes, SA, 5095, Australia.
Future Industries Institute, University of South Australia, Mawson Lakes, SA, 5095, Australia.
Chemosphere. 2023 Aug;331:138850. doi: 10.1016/j.chemosphere.2023.138850. Epub 2023 May 3.
Pesticides play an important role in conventional agriculture by controlling pests, weeds, and plant diseases. However, repeated applications of pesticides may have long lasting effects on non-target microorganisms. Most studies have investigated the short-term effects of pesticides on soil microbial communities at the laboratory scale. Here, we assessed the ecotoxicological impact of fipronil (insecticide), propyzamide (herbicide) and flutriafol (fungicide) on (i) soil microbial enzymatic activities, (ii) potential nitrification, (iii) abundance of the fungal and bacterial community and key functional genes (nifH, amoA, chiA, cbhl and phosphatase) and (iii) diversity of bacteria, fungi, ammonia oxidizing bacteria (AOB) and archaea (AOA) after repeated pesticide applications in laboratory and field experiments. Our results showed that repeated applications of propyzamide and flutriafol affected the soil microbial community structure in the field and had significant inhibitory effects on enzymatic activities. The abundances of soil microbiota affected by pesticides recovered to levels similar to the control following a second application, suggesting that they might be able to recover from the pesticide effects. However, the persistent pesticide inhibitory effects on soil enzymatic activities suggests that the ability of the microbial community to cope with the repeated application was not accompanied by functional recovery. Overall, our results suggest that repeated pesticide applications may influence soil health and microbial functionalities and that more information should be collected to inform risk-based policy development.
农药在常规农业中通过控制害虫、杂草和植物病害起着重要作用。然而，农药的重复使用可能对非靶标微生物产生持久的影响。大多数研究都在实验室规模上调查了农药对土壤微生物群落的短期影响。在这里，我们评估了氟虫腈（杀虫剂）、丙草胺（除草剂）和氟环唑（杀菌剂）对（i）土壤微生物酶活性、（ii）潜在硝化作用、（iii）真菌和细菌群落丰度和关键功能基因（nifH、amoA、chiA、cbhl 和磷酸酶）以及（iii）细菌、真菌、氨氧化细菌（AOB）和古菌（AOA）多样性的生态毒理学影响，这些影响是在实验室和田间实验中重复使用农药后产生的。我们的结果表明，丙草胺和氟环唑的重复使用会影响田间土壤微生物群落结构，并对酶活性产生显著抑制作用。受农药影响的土壤微生物群落丰度在第二次施药后恢复到接近对照的水平，表明它们可能能够从农药的影响中恢复。然而，农药对土壤酶活性的持续抑制作用表明，微生物群落应对重复施药的能力并没有伴随着功能的恢复。总的来说，我们的结果表明，重复使用农药可能会影响土壤健康和微生物功能，应该收集更多的信息来为基于风险的政策制定提供信息。
