RESEARCH REPORTS FROM INSTITUTE FOR AGRO-MICROBIOLOGY, Vol. 2, 1998 p.97-107
Copyright © Institute for Agro-Microbiology. All Rights Reserved.

---

GRANT REPORT

---

9.A Study on Assessing the Side Effects of Pesticides on Soil Ecosystem

Hiroki Yamamoto, Kazuhito Itoh and Kousuke Suyama(Faculty of Life & Environmental Science, Shimane University)

In the early 1970's, there were indications that regulatory authorities in Europe were considering the introduction of the requirement for tests of pesticides effects on soil microflora. Several workshops were held in Europe and recommendations for testing were drawn up by the participants and published. Also in Japan, similar meetings have been organized to produce arguments for the most meaningful tests, and a draft recommendation for the testing of side-effects of pesticides on soil microflora was proposed. The draft includes several test parameters extracted for both upland and paddy soil.
As part of our evaluation of the proposed method, we examined the precision of the test method for each parameter described in the recommendation, and also we studied the effects of bensulfuron methyl on 'ammonification', 'nitrification' and 'microbial biomass' using the proposed test method. The herbicide, applied at the recommended rate to paddy field soil, has no significant effect on 'ammonification and 'microbial biomass'. The chemical, however, appears to have a temporary adverse effect on 'nitrification', and a complete recovery was evident at 28 days.

Keywords: Pesticide, Assessment, Side-effect, Soil microorganism, Microbial activity