Effect of soil properties on the persistence of carbamate pesticides.
Persistence of six carbamate pesticides (oxamyl, I; carbaryl, II; phorate, III; phosphomidon, IV; carbofuran, V and methomyl, VI) on ten different soils of Aligarh district was investigated in the laboratory incubated conditions under different moisture levels; temperature; pesticide concentration; acidic, neutral and alkaline pH; FYM (farm yield manure) and nitrogen concentration. The process of degradation followed first order kinetics. The rate of degradation of all the six carbamate pesticides in studied soils was found to increase with rise in temperature, moisture content, amount of FYM or N and decrease with increasing pesticidal concentration. The degradation was more rapid in alkaline medium than neutral or acidic medium. The values of activation energies (Ea) showed that the degradation of pesticides in soils is due to microbial activity and probably enzymatic. The degradation of pesticides was in the order I > VI > V > IV > II > III. The degradation of pesticides in different soils was in the order S1 > S2 > S3 > S4 > S5 > S6 > S7 > S8, > S9 > S10.
Chemistry Department, D.S. College, Aligarh (U.P.). drop31@rediffmail.com
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Bansal
D002219:Carbamates / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D009584:Nitrogen / Q000032:analysis; D012987:Soil; D012989:Soil Pollutants / Q000032:analysis*; D013696:Temperature
D002219:Carbamates; D012987:Soil; D012989:Soil Pollutants; D009584:Nitrogen