Effect of Pesticides On Certain Soil Biological and Biochemical Indices of a Paddy Soil

(整期优先)网络出版时间:2003-01-11
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A21-daylaboratoryincubationexperimentwasconductedtoinvestigatetheimpactofpesticides(Triazophos,ButachlorandJinggangmycin)onapaddyfieldsoilhealthundercontrolledmoisture(floodedsoil)andtemperature(25℃)conditions.Theelectrontransportsystem(ETS)/dehydrogenaseactivitydisplayedanegativecorrelationwithpesticidesconcentrations,andtheactivitywasaffectedadverselyastheconcentrationofthepesticidesincreased.Thehigherdosesofpesticides,5and10foldsfieldrates,significantlyinhibitedETSactivity,whilelowerratesfailedtoproduceanysignificantreducingeffectagainstthecontrol.TherelativetoxicitylevelofpesticidesindecreasingtheETSactivitywasinthefollowingorder;Triazophos>Jinggangmycin>Butachlor,irrespectiveoftheirratesofapplication.Thepesticidescausedanimprovementinthesoilphenolcontentanditincreasedwithincreasingtheconcentrationofagrochemicals.Thepesticideincorporationdidnotproduceanysignificantchangeinsoilproteincontent.TheresponseofbiomassphospholipidcontentwasnearlysimilartoETSactivity.ThephospholipidcontentwasdecreasedwiththeadditionofpesticidesinthegivenorderofTriazophos>Jinggangmy-cin>Butachlor;andthetoxicitywasintheorder:10FR(timesoffieldrate)>5FR~>1.0FR>0.5FR>control.