College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China.
Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China.
Ecotoxicol Environ Saf. 2019 Apr 30;171:493-501. doi: 10.1016/j.ecoenv.2019.01.017. Epub 2019 Jan 10.
Roxarsone (ROX), an organoarsenic feed additive, occurs as itself and its metabolites including As(V), As(III), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) in animal manure. Animal manure improves soil biological property, whereas As compounds impact microorganisms. The integral influence of animal manure bearing ROX metabolites on soil biological quality is not clear yet. Herein, the effect of four chicken manures excreted by chickens fed with four diets containing 0, 40, 80 and 120 mg ROX kg, on soil biological attributes. ROX addition in chicken diets increased total As and ROX metabolites in manures, but decreased manure total N, ammonium and nitrate. The elevated ROX metabolites in manures increased soil total As, As species and total N, and increased first and then decreased soil nitrate and nitrite, but did not affect soil ammonium in manure-applied soils. The promoting role of both soil As(III) and ammonium on soil microbial biomass carbon and nitrogen, respiration and saccharase activity, were exceeded or balanced by the inhibiting effect of soil nitrate. The suppression of soil catalase activity by soil As(V) was surpassed by the enhancement caused by soil nitrate and nitrite. Soil urease, acid phosphatase and polyphenol oxidase activities were not suitable bioindicators in the four manure-amended soils. Soil DMA did not affect soil biological properties, and MMA was not detectable in all manure-amended soils. The above highlights the complexity of joint influence of soil As and N on biological attributes. Totally, when ROX is used at allowable dose in chicken diet, soil biological quality would be suppressed in manure-amended soil.
罗欧砷（ROX）是一种有机砷饲料添加剂，以其本身及其代谢物的形式存在于动物粪便中，包括砷（V）、砷（III）、一甲基砷酸（MMA）和二甲基砷酸（DMA）。动物粪便可以改善土壤生物特性，而砷化合物会对微生物产生影响。目前尚不清楚含有 ROX 代谢物的动物粪便对土壤生物质量的综合影响。本文研究了四种鸡粪（由分别采食四种含 0、40、80 和 120mg/kgROX 的日粮的鸡排泄）对土壤生物特性的影响。鸡日粮中添加 ROX 会增加粪便中总砷和 ROX 代谢物的含量，但会降低粪便中总氮、铵态氮和硝态氮的含量。粪便中 ROX 代谢物含量的增加会导致土壤中总砷、砷形态和总氮的增加，随后土壤中硝态氮和亚硝态氮的含量先增加后减少，但对施用鸡粪的土壤中铵态氮没有影响。土壤砷（III）和铵态氮对土壤微生物生物量碳和氮、呼吸作用和蔗糖酶活性的促进作用被土壤硝态氮的抑制作用所抵消或平衡。土壤中砷（V）对土壤过氧化氢酶活性的抑制作用被土壤中硝态氮和亚硝态氮的增强作用所超越。土壤脲酶、酸性磷酸酶和多酚氧化酶活性不适用于四种添加鸡粪的土壤中的生物指标。土壤中没有检测到 DMA，而 MMA 也没有在所有添加鸡粪的土壤中被检测到。上述结果突出了土壤砷和氮对生物特性的联合影响的复杂性。总的来说，当 ROX 在鸡日粮中的使用剂量在允许范围内时，添加鸡粪会降低土壤生物质量。
