Pathogens may reach agricultural soils through application of animal manure and thereby pose a risk of contaminating crops as well as surface and groundwater. Treatment and handling of manure for improved nutrient and odor management may also influence the amount and fate of manure-borne pathogens in the soil. A study was conducted to investigate the leaching potentials of a phage (Salmonella enterica serovar Typhimurium bacteriophage 28B) and two bacteria, Escherichia coli and Enterococcus species, in a liquid fraction of raw pig slurry obtained by solid-liquid separation of this slurry and in this liquid fraction after ozonation, when applied to intact soil columns by subsurface injection. We also compared leaching potentials of surface-applied and subsurface-injected raw slurry. The columns were exposed to irrigation events (3.5-h period at 10 mm h−1) after 1, 2, 3, and 4 weeks of incubation with collection of leachate. By the end of incubation, the distribution and survival of microorganisms in the soil of each treatment and in nonirrigated columns with injected raw slurry or liquid fraction were determined. E. coli in the leachates was quantified by both plate counts and quantitative PCR (qPCR) to assess the proportions of culturable and nonculturable (viable and nonviable) cells. Solid-liquid separation of slurry increased the redistribution in soil of contaminants in the liquid fraction compared to raw slurry, and the percent recovery of E. coli and Enterococcus species was higher for the liquid fraction than for raw slurry after the four leaching events. The liquid fraction also resulted in more leaching of all contaminants except Enterococcus species than did raw slurry. Ozonation reduced E. coli leaching only. Injection enhanced the leaching potential of the microorganisms investigated compared to surface application, probably because of a better survival with subsurface injection and a shorter leaching path.
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机译：病原体可能会通过施加动物粪便而进入农业土壤，从而有污染农作物以及地表水和地下水的风险。粪肥的处理和处理以改善营养和气味管理也可能影响土壤中粪便传播的病原体的数量和命运。进行了一项研究，以研究通过固液分离得到的生猪粪便的液体部分中噬菌体（肠炎沙门氏菌鼠伤寒沙门氏菌28B）和两种细菌（大肠杆菌和肠球菌）的浸出潜力。臭氧处理后的液体馏分，当通过地下注入应用于完整的土壤柱时。我们还比较了表面和地下注入的原始浆料的浸出潜力。孵育1、2、3和4周并收集渗滤液后，将色谱柱暴露在灌溉事件下（3.5 h，10 mm h -1 ）。到培养结束时，确定了在每种处理的土壤中以及在注入了原始浆液或液体馏分的非灌溉柱中微生物的分布和存活。通过平板计数和定量PCR（qPCR）对渗滤液中的大肠杆菌进行定量，以评估可培养和不可培养（存活和不可存活）细胞的比例。与原始浆液相比，浆液的固液分离增加了液体馏分中污染物的在土壤中的重新分布，并且在四个浸出事件之后，液体馏分的大肠杆菌和肠球菌物种的回收率高于原始浆液。液体馏分也导致除肠球菌以外的所有污染物的浸出要比原料浆更多。臭氧化仅减少了大肠杆菌的浸出。与表面施用相比，注射增强了所研究微生物的浸出潜力，这可能是因为地下注射具有更好的存活率和更短的浸出路径。
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