(upon last of parents to die, three sons owned farmland as tenants-in-common and operated farm as joint venture until sometime in 2005; in 2005 sons agreed to approximately equal division of farm based on survey; agreement broke down and partition action filed; one son filed counterclaim asserting adverse possession; trial court, on adverse possession claim determined that usage was permissive during parents' lifetimes and property divided; on appeal, court affirmed on basis that prior use was permissive and not adverse; trial court's use of equalized value approach to dividing property within court's discretion).