With the introduction of new Aphanomyces root rot (Aphanomyces eutieches Drechs.) resistance alfalfa varieties, it is important to know how best to position these products for dairy and alfalfa producers. To help understand the extent and range of soils infested with the Aphanomyces root rot organism, we conducted a survey of soils in the dominant forage producing counties of Wisconsin and Sutheastern Minnesota. Our goals included testing for the presence of Aphanomyces root rot race 1 and/or race 2. This test also detects the presence of Phytophthora root rot (Phytophthora medicaginis). We collected cropping history data to determine if the disease is more likely expressed in fields with a high frequency of alfalfa in the rotation. Survey results will be summarized and presented in this summary presentation.