Go to your township assessor and talk to him about it. His name and phone number is on your annual assessment notice. Ordinarily, its going to be based on your zoning since they are required to assess you at the "highest and best" use for your property. Also, while Ag property is usually assessed lower, I donʻt remember an Ag tax exemption for real estate taxes. Only sales tax is exempt for farm use in Michigan and then all you have to do is sign an "exempt purchase" form that the seller will supply you at the time of purchase. But I moved away from Bangor/So. Haven about ten years ago, so I might be wrong.