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EFFECT OF CHEMICALS ON SOIL NITRIFYING POPULATIONS USING A CONTINUOUS-FLOW CULTURE TECHNIQUE
Citation:
Hendricks, C. AND A. Rhodes. EFFECT OF CHEMICALS ON SOIL NITRIFYING POPULATIONS USING A CONTINUOUS-FLOW CULTURE TECHNIQUE. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/D-89/221 (NTIS PB90134289).
Description:
This study examines the effects of Roundup [N-(phosphonomethyl)glycine] and N-Serve[2-chloro-6-(trichloromethyl)pyridine] on nitrifying organisms in static batch, perfusion soil columns, and a new continuous-flow soil column system. he continuous-flow method is new to nitrification studies and was shown to produce greater nitrifier activity than either static batch or perfusion techniques. oth products were shown to significantly inhibit nitrification in treated soils over untreated controls. N-Serve completely inhibited nitrification at concentrations >42 ug nitrapyrin g -1 dry soil, and Roundup significantly reduced nitrification at 6.8 and 68 mg glyphosate g -1 dry soil. eterotrophic bacterial populations increased significantly in continuous-flow columns treated with 42 mg nitrapyrin and 68 mg glyphosate g -1 dry soil. Numbers of heterotrophs were not significantly different from controls in soils at lower concentrations. umbers of nitrifying bacteria did not appear to change following treatment, although nitrification was inhibited. luorescent antibody analysis of nitrifiers revealed that Nitrosolobus was more numerous that Nitrosospira and Nitrosomonas. Nitrosolobus increased in number, whereas the other two genera remained unchanged.