A significant number of experiments, many conducted in Wisconsin, show the benefits of adding lime to fields where alfalfa is grown (Peters and Kelling, 1989, 1997). Similarly, a substantial amount of work has documented the benefits of adding potash to soils where alfalfa is raised (Attoe and Truog, 1950; Smith and Powell, 1979; Erickson et al., 1981; Peterson et al., 1975; Kelling, 1995). Potassium functions in several physiological processes in forage legumes. These include enzyme activity, carbohydrate production and transport, and stomatal activity (Munson, 1985). Potassium uptake is also linked to increased resistance to disease and lodging, increased carbohydrate production, and improved winter hardiness of alfalfa (Schulte and Walsh, 1993).