The Effects of composts on adsorption-desorption of three carbamate pesticides in different soils of Aligarh district

The effects of various organic manure [farm yield manure (fym), sewage sludge and poultry manure] application on adsorption-desorption of three carbamate pesticides [oxamyl(i);s-ethyl-nmethylcarbamoyl) oxy]thioacetimidate (ii) and n-phenyl (ethyl carbamoyl) propyl carbamate (iii) on six soil samples of aligarh district was studied. addition of organic manure increased soil organic carbon content and electrical conductance while ph decreased. the results of the study denoted that adsorption isotherms were ‘l’ type and adsorption-desorption data conformed to freundlich adsorption isotherm equation. the adsorption increased with the increase in organic manure and followed the order sewage sludge > fym > poultry manure. the adsorptivity of soils was in order soil no. 1 > 2 > 3 > 4 > 5 > 6. the adsorption capacity was significantly positively correlated with soil organic carbon and cec and negatively correlated with soil ph. desorption was more in unamended soil than manure amended soil and decreased with the increase in amount of organic manure. desorption showed hystersis, indicate by the higher adsorption slope (1/n ads) compared with desorption slope (1/n des).