Carbon dioxide evolution and oxidoreductase enzyme activities in relation to herbicides application in an alluvial soil of Varanasi

Abstract

Laboratory incubation study was carried out in Gangetic alluvial soil of Varanasi at recommended and double the recommended dose of glyphosate, paraquat and pendimethalin to assess their impact on carbon dioxide (CO2) evolution, dehydrogenase & catalase activities and the soil bacterial population. Both stimulating and inhibiting effects were noticed from the application of herbicides glyphosate, paraquat and pendimethalin on the decomposition of organic matter. The rate of periodical changes of CO2 evolution (mg CO2-C g-1 soil) from the herbicides applied soil, followed the order pendiemthalin > paraquat >glyphosate. The dehydrogenase activity (mg TPF g-1 day-1) was more stimulant at double the recommended dose of the herbicides after 42 days of incubation. Both stimulating and/or inhibiting effects were observed on catalase activity (ì mole H2O2 consumed min-1 g-1 soil) and bacterial population in soil as influenced by the herbicides. © 2015, Indian Society of Agricultural Biochemists. All rights reserved.