Land managers often seek to control weedy, exotic species after heavy soil disturbance, while allowing target species to recover.  Cover crops have been proposed as a method to both control exotics and allow the establishment of target plants.  The use of cover crops for revegetation has not been well documented, even though cover crops have been used successfully in agriculture in some cases.  In two experiments in a Fort Riley, Kansas bare-soil field, we are testing whether cover crops could aid in revegetation after disturbance and control weedy, exotic species.  Both experiments compared establishment in plots with or without cover crops. In the first experiment, we sowed cover crops of western wheatgrass (Pascopyrum smithii) or smooth brome (Bromus inermis) along with a mix of native grass species in April 2006.  This experimental design allows us to examine the effects of cover crops on the establishment of target native grasses as well as weedy species from the seed bank.  In the second experiment, which was established in February 2007, we sowed cover crops of six different species representing annuals and perennials of C₃ and C₄ grasses, as well as legumes.  In half of each plot we sowed seed of the exotic weed, yellow sweetclover (Melilotus officinalis), and in all plots we sowed a mix of native plant species.  The experimental design allows us to test whether cover crops in general can control exotic, weedy species and allow the establishment of target native species.  The experimental design also allows us to determine whether cover crops control species most similar to themselves (annual, perennial, legumes, etc.).  These studies build upon a greenhouse study where few effects of cover crops were found, and where yellow sweetclover essentially prevented the establishment of all other species.