ABSTRACT TWO conservation tillage systems were studied and compared with the conventional (plow-disk-plant) tillage system. Runoff, soil loss, and nutrient losses dur-ing the 1973-75 growing seasons were measured for six small, paired watersheds planted to continuous corn (runoff and soil loss for the year, 1972, when conservation tillage systems were being established were also measured). Fifty-nine percent of the soil surface under ridge-planting and 11 percent under till-planting were covered with crop residue, compared to less than 2 per-cent for conventional planting. Conservation tillage systems on the average reduced runoff about 40 percent and reduced soil loss from 60 to 90 percent. Total losses of nitrogen and phosphorus (total P in sediment measured only in 1973) were mostly associated with soil loss and consequently were decreased for conservation tillage systems. Solution phosphorus losses and concen-trations and available P concentrations in sediment (measured in 1974 and 1975) increased with residue cover. Several factors could be responsible, including decreased fertilizer incorporation, selective erosion pro-cesses, and the residue being a phosphorus source. Corn yield data are given.