effect of soil texture and temperature on atrazine degradation and its half-life

abstract in order to study the effects of soil texture and temperature on atrazine degradation, an experiment was conducted in completely randomized design with factorial arrangement and 3 replications. experimental factors included, soil texture (sandy loam and silty clay), temperature(10, 20 and 30 oc) and 4 incubation periods(0, 20, 40 and 60 days). soil was spiked with atrazine at a rate of 50 mg/kg soil and atrazine residue was measured with hplc. results showed that soil texture and temperature had significant effects on atrazine degradation rate.the highest and lowest degradation rate observed in clay soil(30 oc) and sandy soil (10 oc) with degradation rate coefficient of 0.0077 and 0.001, respectively. atrazine half-life in clay soil was lower than sandy soil. at 10, 20 and 30 oc atrazine half-life was 693, 364.5 and 138.6 days for sandy soil and 277.2, 157.5 and 90 days for clay soil, respectively. based on these results it is expected that atrazine persistence would be lower in clay soils with higher temperature. key words: atrazine (aaterax), soil texture, temperature, half-life, persistence