Chromatographic analyses of chlorpyrifos degradation, microorganism counts (bacteria, fungi, and actinomycetes), and total microbial activity in the soils were performed in triplicate. All data are presented as means ± st. dev. The statistical significance of the data were evaluated byone-wayanalysis of variance (ANOVA). A pvalue of less than 0.05 was considered statistically significant unless otherwise indicated. If an overall significance was detected, Tukey's multiple range tests were performed.