PREDICTION OF THE LEACHING RATE OF BORIC-ACID UNDER FIELD CONDITIONS

The adsorption coefficients of boric acid in a sandy loam and an organic loamy clay measured by batch equilibration were about twice as high as by elution from cylinders of soil aggregates. The latter values gave predicted rates of leaching which agreed with those observed in a field experiment under winter rainfall. Adsorption coefficients of weakly adsorbed solutes are easily measured from elution experiments in the laboratory and appear suitable for field use. They avoid the difficulties of incorporating reaction velocity constants and correcting empirically for the number of adsorption sites, which are required when the coefficients are measured by batch equilibration. © 1979.