Trifluralin Dissipation in Soil Following Repeated Annual Applications

Soil residues from annual trifluralin (α,α,α-trifluoro-2,6-dinitro- N,N dipropyl- p -toluidine) applications were determined over a 4-year period on a Sharpsburg silty clay loam at Lincoln, Nebraska. A phytotoxic residue of trifluralin persisted in the soil for 1 or more years especially at above-normal rates of trifluralin. Repeated applications of trifluralin did not cause a significant buildup of trifluralin in the soil. There was little herbicide remaining in the soil during subsequent years from normal rates of trifluralin.