Effect of Micro-Remediation on Enzymes Activity and Available Nutrients in Chlorpyrifos-Polluted Soils

Abstract

In order to find out the effect of micro-remediation on enzyme activity and available nutrient in chlorpyrifos-polluted soils and the correlation of enzyme activity, available nutrients and chlorpyri fos residue during soil remediation process, the soils planting <i>Brassica juncea</i> throughout the year, sprayed with chlorpyrifos and treated with bacteria were selected as restoration land, while the soils only sprayed with chlorpyrifos were regarded as reference land. The results showed that the activities of urease, catalase, amylase and phosphatase in the restoration land were higher than those in the reference land, especially in the subsequent phase of sample time (<i>P</i> < 0.05). Correlation analysis demonstrated that there was significantly negative correlation between amylase activity and chlorpyrifos residue in the soils only sprayed chlorpyrifos, while amylase and catalase activity had a significantly negative correlation with chlorpyrifos residue respectively in the restoration soils (<i>P</i> < 0.01). Meanwhile, just as the soil enzyme activities, the available nutrients content in the restoration soils were higher than those in the soils only sprayed chlorpyrifos, and significant difference for available phosphorus between the two soils (<i>P</i> < 0.05) can be observed. Correlation analysis demonstrated that there was no significant correlation between available nutrients and chlorpyrifos residue in the reference soils, while available phosphorus content was significantly negatively correlated with chlorpyrifos residue in the restoration soils (<i>P</i> < 0.01). In general, the microbial remediation can contribute to effectively enhancing the contents of available nitrogen, available potassium and available phosphorus in soils polluted by chlorpyrifos and improve soil fertility well.