The Twin Watersheds displayed similar runoff characteristics with respect to chemistry and sediment loading for the calibration period of 1993 – 1996. The results from 1997 –the first year the east watershed was converted to zero-tillage – should be interpreted with caution because of unusual runoff conditions.

The proportional contribution to the annual loading by spring runoff and rainfall is largely dependent on the relative volumes of water each runoff contributes annually, and this fluctuated year to year at the Twin Watersheds. However nutrient concentrations were also important, for they do not all follow the same pattern.

Nutrient loading data was similar in magnitude and trends for the Twin Watershed and the South Tobacco Creek (STC) main channel. This suggests on the whole, the entire watershed may respond in a like manner to measures, which initiate responses at the Twin watersheds. However greater stream discharges on the STC main channel will likely continue to result in greater sediment loads because of channel erosion.