Published online by Cambridge University Press: 12 June 2017
The movement and adsorption of soil-applied 14C-labeled 2,4-bis(isopropylamino)-6-(methylthio-s-triazine (prometryne) and 1,1-dimethyl-3-(a,a,a-trifluoro-m-tolyl)urea (fluometuron) in the presence of 0.01 and 0.5 N CaCl2 were studied. The soils were Ca++-saturated Eufaula loamy fine sand and Norge loam. In equilibrium adsorption studies, fluometuron adsorption was decreased and prometryne adsorption was increased by increasing the CaCl2 concentration from 0.01 to 0.5 N. The mobility of prometryne in the two water-saturated soils was decreased by an increase in CaCl2 concentration. Fluometuron mobility was unchanged by the two CaCl2 concentrations in Eufaula, but was greater in Norge at the higher CaCl2 concentration. The adsorption of each herbicide in the flowing system was less than that predicted by the distribution coefficient. Differences in CaCl2 concentration do not appear to influence the mobility of the two herbicides sufficiently at the soil-water flow rate used in this study to require changes in current field application practices.