The effects of seasonlong grazing, short duration, twice-over rotation,and complementary grazing systems, and idle grassland on upland nesting ducks were determined from the results of waterfowl nesting studies,waterfowl pair counts, and visual obstruction readings taken in the vegetation. The visual obstruction readings and available nesting cover were higher (P

Effects of seasonlong grazing, complementary, short-duration,switchback, and twice-over rotation grazing treatments, and non- grazed prairie on upland nesting ducks were evaluated from nesting studies on the Central Grasslands Research Station. Undisturbed cover contained the highest densities of duck nests on the Station. Undisturbed cover consisted of grazing treatments before the initiation of the grazing season, which contained the highest percentage of total duck nests at 58.8%, followed by deferred areas on rotation grazing treatment (16.7%),and an idle area (13.5%). Only 11% of ducks nested on grazed plots.Nesting success in 1987 and 1988 was highest on twice-over rotation grazing system with 49.3 and 34.0 percent, respectively. Nesting success in 1987 and 1988 on an idle area was 16.3 and 7.0 percent, respectively.Ducklings produced was highest on switchback grazing system with 124.3 per 40.5 ha in 1987 and highest on twice-over rotation grazing system with 74.1 per 40.5 h.