代森锰锌对土壤微生物量的影响

The Effect of Mancozeb on Microbial Biomass in Soil

以曲阜地区的土壤（棕壤）为研究对象，通过添加不同农药浓度的代森锰锌来分析土壤中各种微生物量的变化，研究其对土壤微生物的影响作用。结果表明，在试验浓度范围内显示对微生物有“激活→抑制→再恢复”3个阶段。在1～10d呈现不同程度的促进作用，表现出一定的激发效应。到14d以后，出现了抑制效应，且抑制作用不断减弱，接近28d时又逐渐接近对照水平。浓度为0．15mg／L时，代森锰锌可促进细菌、真菌及放线菌的增殖；浓度为1．5、5mg／L时，代森锰锌抑制微生物增殖；随时间的推移，农药的作用逐渐减弱，土壤微生物量趋于土壤中农药含量为零时的微生物量。

By taking brown soil in Qufu region of Shandong Province as the research object, changes of microbial biomass in soil were analysed through adding various amount of mancozeb so as to study the effect of pesticides on soil microorganisms. The results have shown that there were three stages to affect microorganisms in soil, i. e., ＂activating-inhibiting-restoring＂. In the first 10 days, some promotion appeared to present certain activating effect, and after the 14th day, an inhibition effect would come up and then steadily take off. Soil microorganisms would not be restored gradually to approach the control level again until around the 28th day. The proliferation of bacteria, fungi and actinomycetes could be promoted when mancozeb was at concentration of 0.15 mg/L, whilst being inhibited when at 1.5 or 5 mg/L. As time went on, the effect of pesticides would gradually be weakened and microbial biomass in soil would be tending to the level as there were no pesticides in soil.