Microbiological Effects and Persistence of Some Pesticide Combinations in Soil
1973
Hubbell, D. H. | Rothwell, D. F. | Wheeler, W. B. | Tappan, W. B. | Rhoads, F. M.
Zineb, parathion, DDT, and Furadan were applied alone and in combination to field plots, with times and rates of application approximating current agronomic practice for the growth of shade-leaf tobacco in the area of Quincy, Florida. Persistence of the pesticides in the soil and possible effects of the pesticides on relative microbial numbers and nitrification were monitored at 2-week intervals over a period of 16 weeks. Relative numbers of bacteria and actinomycetes in all treatments failed to differ significantly from the untreated control. Fungi increased significantly (5% level) in the parathion + DDT + zineb treatment. There were no other significant differences in microbial numbers. Nitrification, as indicated by levels of NO₃-N, showed no significant difference due to treatments when compared to the control at the 5% level. Parathion applied as a single dose was present in the soil in significantly higher amounts initially when compared with treatments where parathion was applied on a weekly basis. This difference disappeared after 6 weeks. There were no other significant differences in pesticide persistence in the soil.
显示更多 [+] 显示较少 [-]