Effect of organic matter and pH on the adsorption of metalaxyl and penconazole by soils

- The adsorption of non-ionic pesticides on soils is affected by pH.
- At pH < 5, the CsOC/Ce ratio increased as the pH of the medium decreased.
- The effect of pH on adsorption is related to the ionization of carboxylic groups.
- SOM charge had similar effect on CsOC/Ce in the four soils under study.