外源磺胺二甲嘧啶对施用粪肥的菜地土壤中微生物群落多样性的影响

Effects of exogenous sulfadiazine on microbial community diversity in vegetable soil applied with manure

【目的】明确磺胺二甲嘧啶(SM2)随粪便施入土壤对土壤微生物群落造成的影响,为合理进行养殖场周围土壤环境质量评估和施肥管理提供参考依据。【方法】收集养殖场附近未经抗生素污染的粪便和土壤,构建粪便–土壤模型,设置不同SM2添加剂量的处理,分别为对照组(0)、低剂量组(5μg·kg^(-1))、中剂量组(500μg·kg^(-1))和高剂量组(5 000μg·kg^(-1)),并分别于粪便和SM2施入1、7、14和50 d后采集土壤样品,采用Biolog技术以及磷脂脂肪酸(Phospholipid fatty acid,PLFA)标记法对比分析不同处理组土壤微生物群落的碳源利用能力、菌群结构和功能多样性变化。【结果】SM2的施入提高了土壤微生物群落的总体碳源利用能力,中、高剂量组在施入50 d时对除酯类以外的其他碳源利用能力均强于对照组。低剂量组在施入7 d内对各类碳源利用能力增强,中、高剂量SM2的施入可能会影响土壤群落某些优势物种的繁殖和数量分配。随施入时间的延长,土壤微生物群落对不同剂量SM2反应不同,革兰阳性菌、革兰阴性菌以及真菌数量变化显著,放线菌变化不明显。【结论】SM2的施入将长期影响土壤微生物群落的结构与功能多样性。养殖场应及时处理动物排泄物以消除抗生素残留,减少粪肥对土壤环境造成的生态破坏。

【Objective】To determine the effect of sulfadimidine(SM2)applied with manure in soil on microbial community,and provide a basis for reasonably conducting environment quality evaluation and fertilization management of soil around the farm.【Method】Manure and soil around the farm that were not contaminated by antibiotics were collected to construct the manure-soil model.Different SM2 adding dosages were setted,including the control group(0),low dosage group(5μg·kg–1),medium dosage group(500μg·kg–1)and high dosage group(5 000μg·kg–1),and the soil samples were collected on 1,7,14 and 50 days respectively after SM2 application.Biolog technology and phospholipid fatty acid(PLFA)labelling were used to compare and analyze the capacities of carbon source utilization,and the structural and functional diversities of soil microbial communities in different treatments.【Result】The application of SM2 improved the overall carbon source utilization capacity of soil microbial community.After applying SM2 for 50 days,the utilization capacities of medium and high dodage groups to all carbon sources except esters were significantly stronger than those of the control group.The capacities of low dodage group utilizing all carbon sources after applying SM2 for 7 days were obviously enhanced.The applications of medium and high SM2 dosages might affect the propagation and quantity distribution of some dominant flora in soil community.With the extension of SM2 application time,the responses of soil microbial community to SM2 at different dosages was different.The quantity changes of Gram-positive bacterium,Gram-negative bacterium and fungi were significant,while the change of actinomycetes number was not obvious.【Conclusion】The application of SM2 will affect the structural and functional diversities of soil microbial communities for a long time.The farm should dispose animal excrements in time to eliminate antibiotic residues,and reduce the ecological damages to soil environment.