(plaintiff bought three parcels of farmland in 1998 totaling 200 acres with intent to restore the land to wetlands and convert the land into a wetland mitigation bank; land preserved by permanent conservation easement and obtained approval to sell credits to developers; at time of purchase, land qualified under state law “current agricultural use valuation” (CAUV) statute for reduced tax valuation; county auditor initially approved CAUV classification for plaintiff, but reversed position nine years later; county board of revision upheld auditor’s determination; trial court reversed; on further review, court of appeals upheld trial court’s reversal on basis that statute classifies “land devoted exclusively to agricultural use” includes land “devoted to and qualified for payments or other compensation under a land…conservation program under an agreement with an agency of the federal government”; definition of “agriculture” constitutional).