摘要
农药对土壤微生物的影响已成为评价农药对土壤生态安全的一个重要指标。采用室内培养法研究了乐果在3种不同质量分数下对土壤微生物种群数量以及土壤中占优势的细菌、真菌和放线菌生长速率的影响。结果表明,以真菌种群受抑制最大,放线菌次之,细菌最小。在供试质量分数下,该杀虫剂对土壤细菌种群数量的影响较复杂,没有明显规律;对土壤真菌和放线菌种群数量的影响均表现为明显的抑制作用,且随药剂质量分数的提高和加药时间的延长抑制趋势越明显。因此,可以选择真菌和放线菌作为土壤受乐果污染的敏感指示菌。结果同时表明,50～500mg·kg-1的乐果不影响细菌的生长速率,而5000mg·kg-1的乐果在加药后2～5d明显抑制其生长速率,加药后6～7d,又恢复到正常水平;3种不同质量分数的乐果在加药后2～7d对真菌和放线菌的生长速率均表现明显的抑制作用,且随药剂质量分数的提高而逐渐增强,但随加药时间的延长又逐渐恢复。
The effect of pesticides on microbial in soil is usually used as an important guide line for estimating the ecological safty of soil. The effects of dimethoate on the microbial populations and the growth of ascendent bacteria, funguses and actinomyces in soil at three different concentrations were studied by indoor culture method. The results showed that the order of the aerobic microorganisms restrained by demethoate was fungi 〉 actinomyces 〉 bacteria. The effect of the insecticide on bacteria population was no obvious rule. It markedly restrained the populations of fungi and actinomyces in soil. And the restraining trend was more obvious with concentration increasing of the insecticide and the prolonging of time. Accordingly, fungi and actinomyces may be used as sensitive indicator in dimethoate＇s contaminative soil. The results synchronously showed the dimethoate had no effect on the growth speed of bacteria at 50-500 mg·kg^-1, but restrained the growth speed of bacteria at 5 000 mg·kg^-1 at 2-5 d, but recovered normal level at 6-7 d. The dimetboate of three different concentrations obviously restrained the growth speed of fungi and actinomyces at 2-7 d. And the restraining effect was more obvious with concentration increasing of the insecticide, but gradually recovered.
出处
《生态环境》
CSCD
北大核心
2007年第2期416-420,共5页
Ecology and Environmnet
基金
中国热带农业科学院基金项目(Rky0707)
关键词
乐果
细菌
真菌
放线菌
敏感指示菌
dimethoate
bacteria
funguses
actinomyces
sensitive indicator
