Effect of glyphosate on the microbial activity of two Brazilian soils

被引:250
作者
Araújo, ASF
Monteiro, RTR
Abarkeli, RB
机构
[1] Ctr Energia Nucl Agr, BR-13400970 Piracicaba, SP, Brazil
[2] EMBRAPA, Meio Ambiente, BR-13820000 Jaguariuna, SP, Brazil
基金
巴西圣保罗研究基金会;
关键词
biodegradation; herbicide; oxisol; ultisol; DEGRADATION; ADSORPTION;
D O I
10.1016/S0045-6535(03)00266-2
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
Glyphosate [N-(phosphonomethyl)-glycine] is a broad-spectrum, non-selective, post-emergence herbicide that is widely used in agricultural. We studied, in vitro, changes in the microbial activity of typical Hapludult and Hapludox Brazilian soils, with and without applied glyphosate. Glyphosate was applied at a rate of 2.16 mg glyphosate kg(-1) of soil and microbial activity was measured by soil respiration (evolution of CO2) and fluorescein diacetate (FDA) hydrolysis over a period of 32 days. We found an increase of 10-15% in the CO2 evolved and a 9-19% increase in FDA hydrolyses in the presence of glyphosate compared with the same type of soil which had never received glyphosate. Soil which had been exposed to glyphosate for several years had the strongest response in microbial activity. Most probable number (MPN) counts showed that after 32 days incubation the number of actinomycetes and fungi had increased while the number of bacteria showed a slight reduction. After the incubation period, high pressure liquid chromatography (HPLC) detected the glyphosate metabolite aminomethyl phosphonic acid (AMPA), indicating glyphosate degradation by soil microorganisms. (C) 2003 Elsevier Science Ltd. All rights reserved.
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页码:799 / 804
页数:6
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