BIOACTIVITY OF ATRAZINE IN NINE SASKATCHEWAN SOILS

Abstract

Bioactivity of atrazine was determined for nine Saskatchewan soils. The amount of the herbicide required to reduce the growth of shoots by 50%, GR50, was estimated from dose-response data, using logistic regression curves. GR50 values varied from 0.09 μg/g for Asquith sandy loam to 1.73 μg/g for Melfort silty clay loam. Using rank correlation coefficients, it was shown that there was a significant correlation of GR50 with soil organic matter content. In addition, when the amorphous oxides of Al and Fe were extracted with pyrophosphate, each also showed a high correlation with GR50.Key words: Bioactivity, atrazine, GR50