Leaching Patterns of Pesticides as Related to Sorption and Porosity Properties of Soils
نویسندگان
چکیده
The influence of adsorption-desorption phenomena and distribution of pore sizes on lhe leaching beh.viour of two herbicides, thiazafluron (highly polar, nonionic) and clopyralid (anionic) in three soils has been studied. Adsorption d.ta, obtained by b.tch equilibriwn, were fitted to Freundlich equation and Kf values calculated. Pore size distribution of the soils was studied by mercury porosimetry. Mobility has been studied by leaching in handpacked soil columns and lhe retardation factor (Ri) calculated as the pore volumes required for leaching 50 % afthe applied herbicide. Rf and Kf values correlated directIy in the case of thiazafluron. Rf and mean pore raruus were inversely related in both cases.
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