Iowa Code Title V. Agriculture [Chs. 159-215A] § 210.6. Dry measure

The unit or standard measure of capacity for substances not liquids from which all other measures of such substances shall be derived and ascertained shall be the standard half-bushel secured in accordance with the provisions of section 210.1. The peck, half-peck, quarter-peck, quart, pint, and half-pint measures for measuring commodities which are not liquids, shall be derived from the half-bushel by successively dividing the cubic inch capacity of that measure by two.