尿素和多效唑对苯磺隆胁迫土壤微生物数量的影响

对盆栽试验不同时间采样,采用平板菌落计数法,研究了添加尿素和多效唑对苯磺隆胁迫土壤微生物数量的动态影响。结果表明,添加尿素、多效唑显著提高了土壤细菌、放线菌和真菌的数量。对土壤细菌的刺激作用具体表现为:最初7 d,苯磺隆+尿素>苯磺隆+尿素+多效唑>苯磺隆+多效唑;14～60 d,苯磺隆+尿素+多效唑>苯磺隆+尿素>苯磺隆+多效唑;与对照相比,1~60 d平均激活率最高达552.7%。对土壤放线菌的刺激作用表现为:苯磺隆+尿素+多效唑>苯磺隆+尿素>苯磺隆+多效唑,与对照相比,平均激活率最高为157.7%。对土壤真菌的刺激作用,不同浓度苯磺隆添加尿素、多效唑的影响比较复杂,与对照相比,平均激活率最高为80.1%。添加尿素、多效唑能够减缓甚至消除苯磺隆对土壤微生物的毒害作用,对除草剂污染土壤中微生物的恢复起促进作用。

Effect of Urea and Paclobutrazol to the Number of Soil Microorganism under Tribenuron Stress

A pot experiment was conducted to research the dynamic effect of urea and paclobutrazol on the number of soil microganism under tribenuron stress by plate counts for colonies at different sampling time.The results showed that urea and paclobutrazol significantly increased the number of soil bacteria,fungi and actinomycetes.Stimulative effect on soil bacteria was that： Tribenuron ＋ urea 〉 Tribenuron ＋ urea ＋ Paclobutrazol 〉 Tribenuron ＋ Paclobutrazol for the first 7 days;Tribenuron ＋ urea ＋ Paclobutrazol 〉 Tribenuron ＋ urea 〉 Tribenuron ＋ Paclobutrazol during14～60 days.Compared with the control,the average activation rate during 1 to 60 days was up to 552.7%.To soil actinomycetes,Tribenuron ＋ urea ＋ Paclobutrazol 〉 Tribenuron ＋ urea 〉 Tribenuron ＋ Paclobutrazol;Compared with the control,the average activation rate was up to 157.7%.To soil fungi,the effect of different concentration of tribenuron with urea and paclobutrazol was complex.Compared with the control,the average activation rate was up to 80.1%.Adding urea or paclobutrazol could alleviate or even eliminate toxicity effect of tribenuron on soil microorganism,and promote the recovery in soil microorganism contaminated by herbicides.