Crown vetch (Coronilla varia) control strategy for Lost Mound sand prairie

Crown vetch (Coronilla varia) is an aggressive non-native legume species that forms dense monospecific mats and crowds out native grasses, forbs, and even shrubs. It is the most serious invasive species threat in the sand prairies at the former Savanna Army Depot (hereafter Lost Mound) and has high potential to fundamentally alter the sand prairie plant communities. Crown vetch may cause declines of some of the 13 state-listed plants species, reductions of other native plants, and diminished habitat quality for grassland birds. In addition, crown vetch is a nitrogen-fixing plant and alters soil properties by increasing nitrogen availability and facilitating the growth of nitrogen-limited plant species including many other non-native species. Because crown vetch is widespread at Lost Mound and herbicides are expensive, we undertook this project to examine the effectiveness of three different chemicals for killing crown vetch in order to develop a more efficient control strategy.