Effects of repeated applications of fungicide carbendazim on its persistence and microbial community in soil  

作　　者：YU Yunlong,CHU Xiaoqiang,PANG Guohui,XIANG Yueqin,FANG Hua Department of Plant Protection,College of Agriculture and Biotechnology,Zhejiang University,Hangzhou 310029,China. 

出　　处：《Journal of Environmental Sciences》2009年第2期179-185,共7页环境科学学报（英文版）

基　　金：supported by the National Natural Sci-ence Foundation of China (No. 30771254);the Zhejiang Provincial Natural Science Foundation (No. Z306260);the National Key Technology R&D Program of China (No.2006BAI09B03);Hi-Tech Research and Development Program (863) of China (No. 2007AA06Z306 );the Program for New Century Excellent Talents in University.

摘　　要：Carbendazim, a systemic benzimidazole fungicide, is applied repeatedly to control plant diseases including soilborne diseases, over a growing season. Studies were carried out under laboratory conditions to assess the effects of repeated carbendazim applications on its persistence and microbial community in soil. The results indicate that dissipation of carbendazim in soil was accelerated with its application frequency. The degradation rate constant of carbendazim was increased significantly from 0.074 d-1 to 0.79 d-1. The corresponding half-life was shorten markedly from 9.3 d to 0.9 d after four repeated applications. No significant inhibitory effect of carbendazim on soil microbial utilization of the carbon sources was observed after first treatment, but a slight increase in average well color development （AWCD） was shown after second, third, and fourth applications. It suggested that soil microorganisms become adapted to carbendazim after repeated application. Simpson and Shannon indexes of soil microbial community from carbendazim treated soil were also similar to those from the control soil, indicating that the richness and dominant character of soil microorganisms remain unchangeable after repeated application. However, after first, second, and third addition of carbendazim, McIntosh indexes on day 21 were significantly higher compared with the control, suggesting that balance of soil microorganisms was altered due to the enrichment of the specific carbendazim-adapting strains in soilCarbendazim, a systemic benzimidazole fungicide, is applied repeatedly to control plant diseases including soilborne diseases, over a growing season. Studies were carried out under laboratory conditions to assess the effects of repeated carbendazim applications on its persistence and microbial community in soil. The results indicate that dissipation of carbendazim in soil was accelerated with its application frequency. The degradation rate constant of carbendazim was increased significantly from 0.074 d-1 to 0.79 d-1. The corresponding half-life was shorten markedly from 9.3 d to 0.9 d after four repeated applications. No significant inhibitory effect of carbendazim on soil microbial utilization of the carbon sources was observed after first treatment, but a slight increase in average well color development （AWCD） was shown after second, third, and fourth applications. It suggested that soil microorganisms become adapted to carbendazim after repeated application. Simpson and Shannon indexes of soil microbial community from carbendazim treated soil were also similar to those from the control soil, indicating that the richness and dominant character of soil microorganisms remain unchangeable after repeated application. However, after first, second, and third addition of carbendazim, McIntosh indexes on day 21 were significantly higher compared with the control, suggesting that balance of soil microorganisms was altered due to the enrichment of the specific carbendazim-adapting strains in soil

关 键 词：CARBENDAZIM DEGRADATION soil microorganism repeated application 

分 类 号：X53[环境科学与工程—环境工程]