Abstract:

The residue of atrazine in soil will cause injury to soybean and other sensitive crops, as well as harm to the human body and environment. To establish efficient remediation techniques for atrazine-contaminated soil, this study carried out the isolation and screening of atrazine-degrading bacteria strains, and compared the effects of different application methods on soil remediation. Using atrazine as substrate, the degrading bacteria were isolated from soil samples with long-term application of atrazine. The degrading bacteria were identified based on colony morphology, 16S rRNA gene sequence and phylogenetic analysis. Through the germination test, the alleviating effect of degrading bacteria on the inhibition of soybean germination by atrazine was verified. Pot experiment was conducted to compare the effects of different application methods on alleviating atrazine harm, including flushing application before sowing (Pre), seed soaking (SS) and flushing application after sowing (Post). The results showed that a highly efficient atrazine degrading strain Zatd001 was screened and identified as Paenarthrobacter sp. The strain Zatd001 could effectively alleviate the inhibition of atrazine on soybean seed germination. All the three application methods could significantly reduce the toxicity of atrazine to soybean plants, and there was no significant difference in soybean growth indexes between treated and blank groups. The order of repair effect of the three application methods was: Pre > Post > SS, but the differences among the three methods were not significant. These results indicate that strain Zatd001 could effectively alleviate the harm caused by atrazine residue to soybean, and its application method is flexible and convenient. This study has important practical significance for the application of degrading bacteria in the remediation of atrazine contaminated soil.

Key words: atrazine, degrading bacteria, application method, soil remediation, soybean