Enzymological Properties of Three Soil Hydrolases and Effects of Several Pesticides on Their Activities*

Abstract

Effects of pesticides on the activities of acid phosphatase, arylesterase and aryl acyl-amidase in soil were examined under upland field and/or laboratory conditions. We established methods to assay the activities of arylesterase and aryl acylamidase, while a known method was applied for acid phosphatase. Fenitrothion EC, chlorothalonil WP and paraquat SL were the main pesticides used and trichlorfon was additional for laboratory tests. Effects of the pesticides on the activities of acid phosphatase and arylesterase in soil were small or moderate when they were applied at conventional and 5-fold rates. Trichlorfon and fenitro-thion EC inhibited the activity of aryl acylamidase, but the effect was temporary and the activity seemed to easily recover with the degradation of the pesticides or the proliferation of microorganisms. © 1990, Pesticide Science Society of Japan. All rights reserved.