4种熏蒸剂对土壤微生物特性的影响

Effects of 4 Fumigants on Soil Microbial Characteristics

为了研究1,3-二氯丙烯、二甲基二硫、威百亩、甲酸甲酯4种土壤熏蒸剂处理7天对土壤微生物特性的影响。通过室内培养试验,采用稀释平板法测定土壤微生物细菌、放线菌和真菌的数量变化;熏蒸提取-茚三酮法测定土壤微生物生物量氮;直接吸收法测定土壤基底呼吸作用及基底诱导呼吸作用;高锰酸钾滴定法测定土壤过氧化氢酶活性及紫外分光光度法测定土壤中脱氢酶和淀粉酶活性。结果表明:按照熏蒸剂与土壤质量比为25mg/kg的浓度胁迫条件下,熏蒸结束7天后4种熏蒸剂均显著减少土壤中细菌和放线菌的数量以及微生物生物量氮,但对真菌影响效果不大;1,3-二氯丙烯和威百亩能显著抑制土壤基底呼吸作用;威百亩对土壤酶活的影响效果显著。由此得出4种熏蒸剂均会对土壤微生物特性产生一定影响,尤以威百亩效果最显著,其次为1,3-二氯丙烯,而甲酸甲酯和二甲基二硫在影响微生物数量及微生物生物量氮方面效果显著。

In order to research the effects of 4 kinds of soil fumigation such as the 1,3-dichloropropylene,dimethyl disulfide,metham sodium and formic acid methyl ester on the soil microbes characteristics after fumigation a week,and the experiments determined the quantity changes of soil microbial bacteria,fungi and actinomyces with dilution plate method through the indoor culture experiments.Soil microbial biomass nitrogen was determined by fumigation extraction-ninhydrin method;soil respiration was known by absorbed directly method;catalase activity was determined by permanganate titration;the activity of dehydrogenase and amylase were measured by ultraviolet spectrophotometric method.The results showed that,after fumigation 7 days 4 kinds of soil fumigation all significantly reduced the number of soil bacteria and actinomyces and microbial biomass nitrogen,but it had less effects on fungi.Also 1,3-dichloropropylene and metham sodium could significantly inhibited soil respiration.Among this,the effects of metham sodium on soil enzyme activity were most significant.Thus,4 kinds of soil fumigation all took some effects on soil microorganism and metham sodium had the most significant,the next was dimethyl disulfide,but 1,3-dichloropropylene and formic acid methyl had some significant on microbial populations and microbial biomass nitrogen.