The individual and simultaneous effects of Cu and cypermethrin upon glycosidase, phosphomonoesterase and the total microbial activity of soil.

Abstract

Enzymatic and microbial assays are frequently used in the determination of the response of soil organisms to external pollutants. Enzymes and soil microorganisms are particularly used as bioindicators to determine the health and quality of soil following a chemical disturbance. This study chose β- glycosidase, phosphomonoesterase and the total microbial activity of soil to establish the chemical disturbance of pyrethroid insecticide cypermethrin and CuSO4, the main chemical component of widely used Bordeaux mixture. Both were applied individually and as a simultaneous mixture. Results show the greatest negative impact of the joint contamination is upon phosphomonoesterase. Little to no effects are detected at higher concentrations to the total microbial activity, and a positive impact to glycosidase is observed. This study indicates that the enzymes most at risk from Cu/cypermethrin toxicity are soil phosphatases, which are enzymes intrinsic to plant growth and development. A depletion of this enzyme in the rhizosphere has serious implications to soil health and subsequent potential damage to agricultural harvests.