Comparison of Different Soil Leaching Techniques with Four Herbicides

Abstract

Herbicide mobility in soils was compared by three laboratory methods. The Rf values calculated from soil thin-layer chromatography correlated closely with those obtained from soil thick-layer chromatography (r = 0.96). Herbicides leached slightly further in slotted column chromatography as compared with the other methods. The working hours required to conduct a study with each method were in the increasing order of thin-layer, thick-layer, and column chromatography. However, the thin-layer method required the longest waiting times, followed by the column and thick-layer chromatography. If radioactive herbicides are not available or obtainable, the thick-layer chromatography is simplest and quickest. The relative mobility of herbicides studied was fluometuron [1,1-dimethyl-3-(α,α,α-trifluoro-m-tolyl)urea] > napropamide [2-(α-naphthoxy)-N,N-diethylpropionamide] > terbutryn [2-(tert-butyl-amino)-4-(ethylamino)-6-(methylthio)-s-triazine] > trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine). Less herbicide mobility was observed in heavier soil than in sandy soil.