Most states have Ag. Universities that do soil tests. Some are free and some charge a small fee. Not sure how Wisconsin stacks up but NC State does them for the state of North Carolina. Farmers, landowners and home owners can send them there and get a full report back in a couple of weeks via E-mail. No fee is charged from April 1 to November 30th and it only costs $4 per sample December 1st- March 31st (when farmers are getting their fields tested for spring, Large Volume). These tests are in depth and give you lime and fertilizer requirements for the crop or crops being grown. Contact your local county extension agents for further info or local farmers and garden centers should be able to give you some assistance.