摘要
抽象图像
与表面施用相比，粪肥地下注射减少了养分、抗生素抗性微生物和新出现的污染物的表面径流。关于两种施肥方法对粪肥改良田地中抗生素抗性基因（ARGs）表面转运的影响，目前知之甚少。我们通过表面施用和地下注射以及施用后第一天或第七天的模拟降雨，在田间地块上施用液态奶牛粪便。使用霰弹枪宏基因组测序监测土壤和地表径流中ARG的丰富度、相对丰度（标准化为16s rRNA）和ARG图谱。在施用粪肥的1天内，与未处理的土壤相比，施用粪肥处理的土壤的ARG丰富度高32.5–70.5%，磺酰胺（6.5–129%）和四环素（752–3766%）抗性基因的相对丰度更高（p≤0.05）。第7天，表面施用地块的土壤ARG剖面与，未经改良的土壤。施肥46天后，施肥缝中的土壤ARG剖面比未施肥地块的ARG剖面多样化37%。与地表施用相比，粪肥地下注入地块的地表径流中粪肥相关ARGs的丰度较低，并且具有较低的抗性风险评分。这项研究首次表明，尽管粪肥地下注入减少了径流中的ARG，但它可以为注入狭缝内的ARG升高创造潜在的长期热点。
Abstract
Abstract Image
Compared to surface application, manure subsurface injection reduces surface runoff of nutrients, antibiotic resistant microorganisms, and emerging contaminants. Less is known regarding the impact of both manure application methods on surface transport of antibiotic resistance genes (ARGs) in manure-amended fields. We applied liquid dairy manure to field plots by surface application and subsurface injection and simulated rainfall on the first or seventh day following application. The ARG richness, relative abundance (normalized to 16s rRNA), and ARG profiles in soil and surface runoff were monitored using shotgun metagenomic sequencing. Within 1 day of manure application, compared to unamended soils, soils treated with manure had 32.5–70.5% greater ARG richness and higher relative abundances of sulfonamide (6.5–129%) and tetracycline (752–3766%) resistance genes (p ≤ 0.05). On day 7, soil ARG profiles in the surface-applied plots were similar to, whereas subsurface injection profiles were different from, that of the unamended soils. Forty-six days after manure application, the soil ARG profiles in manure injection slits were 37% more diverse than that of the unamended plots. The abundance of manure-associated ARGs were lower in surface runoff from manure subsurface injected plots and carried a lower resistome risk score in comparison to surface-applied plots. This study demonstrated, for the first time, that although manure subsurface injection reduces ARGs in the runoff, it can create potential long-term hotspots for elevated ARGs within injection slits.

https://pubs.acs.org/doi/abs/10.1021/acs.est.2c00981