Effects of herbicides on soil microorganisms in a paddy soil
除草剂对水稻土微生物的影响

The dynamic relationship between herbicide contamination and microbes was investigated by means of the fumigation-extraction method and BIOLOG-carbon utilization methods. There were three different kinds of herbicides (atrazine, butachlor and metsulfuron-methyl) used as examples. The results showed metsulfuron-methyl applied at 10mg·kg-1 significantly decreased the soil microbial biomass during the initial 10 days and then increased from 10 days to 30 days after application (DAA). The soil microbial biomass was not significantly affected by atrazine and butachlor at the same dose. BIOLOG data revealed that soil microbial diversity did not change during the initial 2 days after herbicides treatment, but a significant change of soil microbial diversity was found from 2 to 30 DAA. It was suggested that metsulfuron-methyl application caused significant decrease in the number of soil microbial community (SMC) followed by an increase. However, the number of SMC was not influenced by atrazine or butachlor.