Preferred Movement of Nonadsorbed Chemicals on Wet, Shallow, Sloping Soils

Preferred movement of chloride and nitrate during runoff events following nutrient application was studied experimentally on 109 m long fields with a hard pan at shallow depth near Ithaca, NY. Chloride and nitrate applications were surface‐applied and incorporated at 36 and 69 m uphill from the collection point. All of the applied chemicals, when surface‐applied on saturated soil, were completely lost in the surface runoff and interflow water. When incorporated, at most 60% of the mass applied was lost. The fraction lost appeared to be related to the initial moisture content of the soil. After a chemical application, the concentration in both runoff and interflow was initially high and then decreased exponentially. The concentrations in the runoff water, interflow, and macropores were approximately equal throughout a runoff event.