Effects of dalapon, atrazine and simazine on denitrification in soil

Abstract

The influence of dalapon (2.2-dichloropropanoic acid), atrazine (6-chloro- N-ethyl- N'-(1-methylethyl)-1, 3,5-triazine-2,4-diamine) and simazine (6-chloro- N, N'-diethyl-1,3,5-triazine-2,4-diamine) on denitrification of nitrate in soil was studied by determining the effects of different amounts of these herbicides on the amounts of nitrate lost and the amounts of nitrite, N 2O and N 2 produced when field-moist and air-dried samples of soil were incubated anaerobically after treatment with nitrate or with nitrate and glucose. The data obtained did not confirm reports that small amounts of these herbicides inhibit denitrification in soil. No inhibition of denitrification was observed when dalapon. atrazine and simazine were applied at the rate of 5, 10, 25 or 100 μg g −1soil in the presence or absence of glucose.