单 位：
广东省农业科学院农业资源与环境研究所农业部南方植物营养与肥料重点实验室广东省养分循环利用与耕地保育重点实验室
关键词：
洛克沙胂;鸡粪;茼蒿;植物有效性;砷累积
摘 要：
为考察有机胂饲料添加剂降解转化后其含砷代谢物在土壤和蔬菜中累积及其植物有效性,利用鸡只喂饲含洛克沙胂饲料后排泄的粪便作为有机肥应用于茼蒿的种植,收获后测定土壤及茼蒿植株不同部位砷形态化合物的组分及含量.结果表明,洛克沙胂的降解产物主要为亚砷酸盐[As(Ⅲ)]、砷酸盐[As(Ⅴ)]、二甲基砷(DMA)、一甲基砷(MMA)、4-羟基苯胂酸(4-HPA)及少量其他未知形态含砷代谢物.经检测,茼蒿地上部的砷化合物仅为As(Ⅲ),地下部为As(Ⅲ)及As(Ⅴ).施用对照鸡粪及含洛克沙胂代谢物鸡粪的茼蒿可食用的地上部As(Ⅲ)及总砷含量均低于我国规定的限量标准,与对照鸡粪相比,施用含洛克沙胂代谢物鸡粪显著提高茼蒿地上部As(Ⅲ)、地下部As(Ⅲ)及地下部As(Ⅴ)含量,提升率分别为13.8%±0.4%~37.4%±6.5%、112.9%±4.5%~123.2%±6.5%及44.4%±2.6%~78.0%±5.1%.添加洛克沙胂代谢物鸡粪显著提高土壤中可提取的As(Ⅲ)及As(Ⅴ)含量,提升率分别为49.1%±4.4%及33.4%±2.3%.3个不同生长阶段茼蒿采收后,添加洛克沙胂代谢物鸡粪土壤中可提取的As(Ⅲ)及As(Ⅴ)仍然比对照处理提高4.9%±1.0%~20.0%±1.2%及11.7%±2.4%~18.0%±4.7%.添加含洛克沙胂代谢物鸡粪的土壤中As(Ⅲ)及As(Ⅴ)的茼蒿吸收率分别比对照鸡粪处理提升25.8%及14.3%.综上所述,砷可通过有机胂→饲料→畜禽→畜禽粪便→土壤途径传递并被蔬菜吸收累积,当季施用含有机胂代谢物鸡粪对蔬菜是安全的,但会增加土壤中含砷代谢物的含量,因此不可忽视连续施用时的累积风险.
作 者：
HUANG Lian-xi;WEI Lan;YAO Li-xian;HE Zhao-huan;ZHOU Chang-min;Key Laboratory of Plant Nutrition and Fertilizer in South Region, Ministry of Agriculture;Guangdong Key Laboratory of Nutrient Cycling and Farmland Conservation, Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences;Academy of Natural Resources and Environment, South China Agricultural University;
单 位：
HUANG Lian-xi%WEI Lan%YAO Li-xian%HE Zhao-huan%ZHOU Chang-min%Key Laboratory of Plant Nutrition and Fertilizer in South Region, Ministry of Agriculture%Guangdong Key Laboratory of Nutrient Cycling and Farmland Conservation, Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences%Academy of Natural Resources and Environment, South China Agricultural University
关键词：
roxarsone;;chicken manure;;Chrysanthemum coronarium;;plant availability;;arsenic accumulation
摘 要：
Roxarsone is an organoarsenic feed additive that can be degraded to other higher toxic metabolites after animal excretion. To investigate the accumulation of arsenic metabolites in soils and vegetables after degradation and transformation of organoarsenic feed additives, feces excreted from chickens fed with feed containing roxarsone were used as organic fertilizer for Chrysanthemum coronarium plants.After harvesting, the composition and content of arsenic compounds in soils and different parts of C. coronarium were measured. Results showed that the degradation products of roxarsone in chicken manure mainly contained arsenite[As(Ⅲ)], arsenate[As(Ⅴ)], dimethylarsinic acid, monomethylarsonic acid, 4-hydroxyphenylarsonic acid, and other unknown arsenic species. Only As(Ⅲ)was detected in shoots of C. coronarium; however, two arsenic species, As(Ⅲ)and As(Ⅴ), were detected in the roots of C. coronarium. Chicken manure containing roxarsone metabolites had significantly higher(13.8% ± 0.4%～37.4% ± 6.5%)As(Ⅲ)in shoots, and significantly higher[112.9% ± 4.5%～123.2% ± 6.5% As(Ⅲ)and 44.4% ± 2.6%～78.0% ± 5.1% As(Ⅴ)] in roots of C. coronarium than that in the control treatment. The addition of chicken manure containing roxarsone metabolites also significantly increased the content of extractable As(Ⅲ)and As(Ⅴ)in soils,with elevated rates of 49.1% ± 4.4% and 33.4% ± 2.3%, respectively. In chicken manure containing roxarsone metabolites amended soils,there was 4.9% ± 1.0%～20.0% ± 1.2% of extractable As(Ⅲ)and 11.7% ± 2.4%～18.0% ± 4.7% of extractable As(Ⅴ)higher than that in the control chicken manure amended soils at the end of the three growth stages in C. coronarium. The average absorption rates of As(Ⅲ)and As(Ⅴ)in C. coronarium were 25.8% and 14.3% higher, respectively, in chicken manure containing roxarsone metabolites than that in the control chicken manure treatment. The results reflected the fact that the toxic element As could be absorbed and accumulated by vegetables via the following route:organoarsenic in feed → animal → animal manure → soil → vegetable. The seasonal application of chicken manure containing organoarsenic metabolite is safe for Chrysanthemum; however, it will increase the As(Ⅲ)metabolite content in soils,and thus the cumulative risk of continuous application can not be ignored.
