A colleague of mine at the University of Wisconsin, Madison, shared with me the collaborative work that his class did with Jefferson County in drafting a Agricultural Preservation and Land Use Plan, developed as an amendment to the comprehensive plan. I have been sharing this will a number of people because it is always fun to learn how other states approach preserving farm land plus the students did an outstanding job. You can view the ppt presentation here   http://www.jeffersoncountywi.gov/UserFiles/Zoning%20and%20Planning/files/plan2010/Jefferson%20Co%20Ag%20Presentation%20and%20Land%20Use%20Plan%20Presentation%204.19.11.pdf   and the draft report here  http://www.jeffersoncountywi.gov/jc/public/jchome.php?page_id=1659     scroll down the page until you find 21 Feb. There you will find the draft plan.

A class in 2007 produced this report on which the 2011 work is built    http://urpl.wisc.edu/academics/workshop/wholedocument.pdf

Jefferson County is situated between Milwaukee and Madison. The preservation model has 3 parts: land use (focus is farmland preservation planning areas and zoning, rezoning policy, long range urban service areas, limited service areas, rural hamlets, environmental corridors, and glacial heritage area), economics (focus is commercial agriculture, niche agriculture and organics, food processing, bioenergy, and agricultural support businesses), and incentives focus is farmland preservation tax credits, agricultural enterprise areas, and purchase of agricultural conservation easements). Wisconsin has a bit of an edge due to a recently passed Chapter 91 of Wisconsin State Statues, Wisconsin Working Lands Initiative. The main components include:
1. Expansion and modernization of the state's Farmland Preservation Planning/Zoning Program. This program allows conditional use permits for rural housing and requires a per acre conversion fee for rezoning.
2. Establishment of an Agricultural Enterprise Area (AEA) Program that allows priority areas for continuation of agricultural use and provides opportunity to increase tax credit.
3. Development of a Purchase of Agricultural Conservation Easement (PACE) Program that encourages/supports voluntary local PACE programs and provides up to $12M in state grants/year.