Fluctuation of the abundance of microorganisms in the carbofuran treated soil

摘要

Carbofuran is a soil applied insecticide and nematocid which is used extensively to control pests of corn and other agricultural crops. However, due to short persistante carbofuran may have a decreased efficiency in pest suppression. This work includes the investigation of dose and exposition duration influence on microorganisms abundance in the soil. Experiment were carried out under laboratory conditions on chernozem soil treated with three dose of carbofuran 3, 6 and 60 mg/kg soil. Microorganisms' abundance was determined by standard microbiological methods. Effect of carbofuran on some groups of microorganisms such as: total number of microorganisms, aminoheterotrophs, aminoautotrophs, fungi, actinomycetes and cellulytic microorganisms depends of dose and exposition duration. By factorial analysis three groups of microorganisms were found differing in susceptibility towards carbofuran. The abundance of first group includes cellulytic microorganisms, fungi and actinomycetes is inhibited 30 days after the treatment. The abundance of second group comprises Bacillus sp. increases 3 days after the treatment. Third group (total number of microorganisms and aminoheterothrophs) are stimulatet by carbofuran presence.