Modeling of rhizosphere influences on interactions between chemical dynamics and effects of veterinary medicines in soil

在第一阶段开发的模拟模型集成了兽药磺胺嘧啶（SDZ）和二氟沙星（DIF）在散装土壤中的化学归宿及其对土壤微生物的后续影响，以及单剂量施用粪肥后对土壤功能的影响。在第二个项目阶段，这种方法被扩展到根际，这是土壤中微生物生长的热点，也是活性根系释放有机化合物的连续来源。抗生素及其主要代谢产物的快、慢吸附、转化和结合残留的形成过程适应于根际环境。开发的土壤功能，结构多样性和阻力动态的影响模型扩展相关的植物-土壤相互作用与实验子项目的密切合作。综合的命运效应模型与运输模型相结合，考虑到根际和植物吸收的异质性。过程参数化的两种抗生素SDZ和DIF在根际和散装土壤与中央围隔实验和几个计划的卫星实验的数据。将利用实地试验的数据对由此产生的综合命运效应模型进行评价。该模型进一步用于开发抗生素诱导效应的结构弹性和功能冗余等指标，评估其风险评估的适用性，并产生新的假设来证实结论。

The simulation models developed in the 1st phase integrate the chemical fate of the veterinary medicines sulfadiazine (SDZ) and difloxacin (DIF) in bulk soil and their subsequent effects on soil microorganisms and on soil functions after single-dose application with manure. In the 2nd project phase, this approach is extended to the rhizosphere, which represents the hotspot of microbial growth in soil and a continuous source of organic compounds released from active roots. The processes of fast and slow sorption, transformation and formation of bound residues of the antibiotics and their main metabolites are adapted to the rhizosphere. The developed effect models for soil functions, structural diversity, and resistance dynamics are extended by relevant plant-soil interactions in close collaboration with the experimental subprojects. The integrated fate-effect model is coupled with a transport model taking heterogeneities of the rhizosphere and plant uptake into account. Processes are parameterized for the two antibiotics SDZ and DIF in rhizosphere and bulk soil with data from the central mesocosm experiment and several planned satellite experiments. The resulting integrated fate-effect models will be evaluated with data from the field experiments. The model is further used to develop indicators such as structural resilience and functional redundancy for antibiotic induced effects, evaluate their applicability for risk assessment and to generate new hypotheses to corroborate the conclusions.