生物炭的应用对杀菌剂在设施草莓和土壤的代谢与积累影响

The environmental conditions of greenhouse make strawberry easy to induce diseases and insect pests, which lead to the frequent use of pesticides, and the continuous harvesting and closed environment make the safety problem of pesticide residues on strawberries easy to occur. Biochar has been widely used in rising agricultural production and ecological remediation, but the influence to the fate of pesticide residues in greenhouse condition is not clear. This project will focus on the typical fungicides of cyprodinil, pyrimethanil, procymidone and procymidone metabolites on three kinds of soil, which is including unamended soil, new biochar amended soil and aged biochar amended soil for 1 years, and study their environmental behavior of pesticide volatilization, photolysis, adsorption and leaching based on the greenhouse conditions. The dynamic uptake of pesticides pot experiment is to explore the transfer process of biochar soil- strawberry root- leaf- fruit, and evaluate the influence of biochar amended soil to the phytoavailability of fungicides. Through the dynamic residue tests after continuous applications of fungicides in greenhouse, the levels of fungicides in amended soil and strawberry plants, and the accumulation contribution ratios of fungicides deposition and root absorption will be obtained. This study will clarify the environmental effects of pesticides after the application of biochar in soil, and also provide theoretical support of biochar for the control of pesticide residue.

设施栽培草莓的环境条件易诱发病虫害，导致农药频繁使用，而连续采摘的生产方式和封闭的环境条件，使草莓易发生农药残留安全问题。生物炭已广泛应用于农业增产和生态修复领域，其应用对设施环境中农药施用后的残留、归趋影响尚不明确。本项目以典型杀菌剂（嘧菌环胺、嘧霉胺和腐霉利及其代谢产物）为研究对象，基于设施条件，对三种土壤（未改良土壤，新制备和老化1年的生物炭改良土壤）中农药的挥发、光降解、吸附和淋溶等环境行为开展研究；通过根系动态吸收农药的盆栽实验，考察杀菌剂在生物炭改良土壤—草莓根系—茎叶—果实的迁移行为，并评价生物炭改良土壤对杀菌剂的植物可利用性影响；通过农药连续施用动态残留试验，获得杀菌剂在改良土壤和草莓植株中的残留水平，明确农药沉降和根系吸收对设施草莓蓄积农药的贡献比例。本项目研究结果将明确生物炭改良土壤使用后对设施条件中农药的环境效应，同时也为基于生物炭的农药残留控制技术提供理论支撑。

设施栽培草莓的环境条件易诱发病虫害，导致农药频繁使用，而连续采摘的生产方式和封闭的环境条件，使草莓易发生农药残留安全问题。生物炭已广泛应用于农业增产和生态修复领域，其应用对设施环境中农药施用后的残留、归趋影响尚不明确。本项目以典型杀菌剂（嘧菌环胺、嘧霉胺和腐霉利及其代谢产物）为研究对象，基于设施条件，对三种土壤（未改良土壤，新制备和老化1年的生物炭改良土壤）中农药的挥发、光降解、吸附和淋溶等环境行为开展研究；通过根系动态吸收农药的盆栽实验，考察杀菌剂在生物炭改良土壤—草莓根系—茎叶—果实的迁移行为，并评价生物炭改良土壤对杀菌剂的植物可利用性影响；通过农药连续施用动态残留试验，获得杀菌剂在改良土壤和草莓植株中的残留水平，明确农药沉降和根系吸收对设施草莓蓄积农药的贡献比例。结果表明新和老化生物炭改良土壤抑制了嘧霉胺、嘧菌环胺和腐霉利从土壤向根迁移，从而降低了叶片中嘧霉胺和腐霉利的残留风险，但叶片中嘧菌环胺残留风险因生物炭使用而提高，因此嘧霉胺存在“土壤-叶片”和“土壤-根-叶片”两条迁移途径，嘧菌环胺迁移路径主要为“土壤-叶片”，腐霉利迁移途径主要为“土壤-根-叶片”；杀菌剂连续施用后，生物炭改良土壤和根中杀菌剂的残留小幅降低，但对于草莓叶片和果实中残留的影响较低，其对草莓残留的影响可忽略不计。本项目研究结果表明生物炭改良土壤降低根际吸收实验中嘧霉胺和腐霉利在设施草莓根和叶片中的残留风险，提高了嘧菌环胺在叶片中的残留，老化生物炭较新生物炭改良土壤没有显著差异，但在连续喷雾实验中的影响可忽略，本实验明确了生物炭改良土壤使用后对设施条件中农药的环境效应，同时也为基于生物炭的农药残留控制技术提供理论支撑