Pesticide adsorption in relation to soil properties and soil type distribution in regional scale

Abstract

Study was focused on the evaluation of pesticide adsorption in soils, as one of the parameters, which are necessary to know when assessing possible groundwater contamination caused by pesticides commonly used in agriculture. Batch sorption tests were performed for 11 selected pesticides and 13 representative soils. The Freundlich equations were used to describe adsorption isotherms. Multiple-linear regressions were used to predict the Freundlich adsorption coefficients from measured soil properties. Resulting functions and a soil map of the Czech Republic were used to generate maps of the coefficient distribution. The multiple linear regressions showed that the KF coefficient depended on: (a) combination of OM (organic matter content), pHKCl and CEC (cation exchange capacity), or OM, SCS (sorption complex saturation) and salinity (terbuthylazine), (b) combination of OM and pHKCl, or OM, SCS and salinity (prometryne), (c) combination of OM and pHKCl, or OM and ρz (metribuzin), (d) combination of OM, CEC and clay content, or clay content, CEC and salinity (hexazinone), (e) combination of OM and pHKCl, or OM and SCS (metolachlor), (f) OM or combination of OM and CaCO3 (chlorotoluron), (g) OM (azoxystrobin), (h) combination of OM and pHKCl (trifluralin), (i) combination of OM and clay content (fipronil), (j) combination of OM and pHKCl, or OM, pHKCl and CaCO3 (thiacloprid), (k) combination of OM, pHKCl and CEC, or sand content, pHKCl and salinity (chlormequat chloride).