From the email I got this in:
Another effective way to prevent rural sprawl is to designate farm or forest land for permanent conservation, i.e. local zoning, a robust local (and state) comprehensive plan requirements and also a strong purchase of development right (PDR) program. When farmers work with each other and decide minimum acres for the future of farming, they are not inclined to think development is the best answer. Skagit County Washington's farmers created a 40 acre minimum lot size for agriculture in 1974. They took this action because they understood the importance of having an adequate contiguous base to farm.
In 1990 after WA State passed its Growth Management Act requiring counties to identify and protect Natural Resource lands (farm, forest & mineral) the farmers got additional sprawl prevention. In the mid 90's the county formed a citizen run board and a PDR program (Skagit Farmland Legacy) that has purchased development rights off of 11,000 acres of the estimated 90,000 zoned Agriculture - Natural Resource Lands. The tax collected is used to match federal, state and private funding.
Now the largest threat to the land base is conversion to other uses -- habitat for fish and wildlife, wetland mitigation banks, road widening, etc. without any mitigation for the loss of ground.
Skagit soils produce in the 1-2 % of the highest yields in the world, and are a major supplier for the region and West Coast's food security. Now the challenge is to remind urban residents where their food comes from and see if they will pay to protect the remaining farms.
There are always threats to farms and forests if we don't have a plan and stick to it. The continued work of Friends of Skagit County for 23 years to stop sprawl and conserve natural resource lands has made a difference in the landscape. Even then, there are continued challenges. When we add food security into public policies and planning, we might make better choices.