Ohio constitution
Article II: legislative
Section 36

Laws may be passed to encourage forestry and
agriculture, and to that end areas devoted exclusively
to forestry may be exempted, in whole or in part, from
taxation. Notwithstanding the provisions of section 2
of Article XII, laws may be passed to provide that land
devoted exclusively to agricultural use be valued for
real property tax purposes at the current value such
land has for such agricultural use. Laws may also
be passed to provide for the deferral or recoupment
of any part of the difference in the dollar amount of
real property tax levied in any year on land valued
in accordance with its agricultural use and the dollar
amount of real property tax which would have been
levied upon such land had it been valued for such year
in accordance with section 2 of Article XII. Laws may
also be passed to provide for converting into forest reserves
such lands or parts of lands as have been or may
be forfeited to the state, and to authorize the acquiring
of other lands for that purpose; also, to provide for the
conservation of the natural resources of the state, including
streams, lakes, submerged and swamp lands
and the development and regulation of water power
and the formation of drainage and conservation districts;
and to provide for the regulation of methods of
mining, weighing, measuring and marketing coal, oil,
gas and all other minerals.