This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Tu, C. M. Search for Related Content PubMed Articles by Tu, C. M. Agricola Articles by Tu, C. M.

 Previous Article  |  Next Article 

Appl Environ Microbiol. 1970 March; 19(3): 479-484
Copyright © 1970 American Society for Microbiology. All Rights Reserved.

Effect of Four Organophosphorus Insecticides on Microbial Activities in Soil ¹

Research Institute, Canada Department of Agriculture, London, Ontario

ABSTRACT

Laboratory tests were conducted with four organophosphorus insecticides, Bay 37289 (O-ethyl O-2,4,5-trichlorophenyl ethylphosphonothioate), diazinon [O,O-diethyl O-(2-isopropyl-4-methyl-6-pyrimidinyl) phosphorothioate], Dursban (O,O-diethyl O-3,5,6-trichloro-2-pyridyl phosphorothioate), and Zinophos (O,O-diethyl O-2-pyrazinyl phosphorothioate), applied to a sandy loam at rates of 10 and 100 µg/g to determine whether these materials caused any serious effects on microbial activities related to soil fertility. All insecticides showed an effect on fungi and bacteria for the first and second week of incubation, but, subsequently, the populations returned to levels similar to those obtained in the controls. All insecticide applications increased ammonium production, but, in some instances, there appeared to be a slight depression of nitrification. Sulfur oxidation was equal to or better than that obtained with untreated soil in most cases. There was no significant effect on phosphorus mineralization. Oxygen consumption indicated that microbial respiration increased in proportion to the concentration of insecticides, suggesting the possibilities of microbial degradation of the insecticides or their degradation products and of uncoupling oxidative phosphorylation.

¹ Contribution no. 431, Research Institute, Canada Department of Agriculture, London 72, Ontario. This work was presented in part at the 69th Annual Meeting of the American Society for Microbiology, Miami Beach, Fla., 4-9 May 1969.