Oregon Revised Statutes Revenue and Taxation § 308A.062

(1) Any land that is within an exclusive farm use zone and that is used exclusively for farm use shall qualify for farm use special assessment under ORS 308A.050 to 308A.128, unless disqualified under other provisions of law.

(2) Whether farmland qualifies for special assessment under this section shall be determined as of January 1 of the assessment year. However, if land so qualified becomes disqualified prior to July 1 of the same assessment year, the land shall be valued under ORS 308.232, at its real market value as defined by law without regard to this section, and shall be assessed at its assessed value under ORS 308.146 or as otherwise provided by law. If the land becomes disqualified on or after July 1, the land shall continue to qualify for special assessment as provided in this section for the current tax year.