Commercial corn-producing area
(4) (A) “Commercial corn-producing area” shall include all counties in which the average production of corn (excluding corn used as silage) during the ten calendar years immediately preceding the calendar year for which such area is determined, after adjustment for abnormal weather conditions, is four hundred and fifty bushels or more per farm and four bushels or more for each acre of farm land in the county. (B) Whenever prior to February 1 of any calendar year the Secretary has reason to believe that any county which is not included in the commercial corn-producing area determined pursuant to the provisions of subparagraph (A) of this subsection, but which borders upon one of the counties in such area, or that any minor civil division in a county bordering on such area, is producing (excluding corn used for silage) an average of at least four hundred and fifty bushels of corn per farm and an average of at least four bushels for each acre of farm land in the county or in the minor civil division, as the case may be, he shall cause immediate investigation to be made to determine such fact. If, upon the basis of such investigation, the Secretary finds that such county or minor civil division is likely to produce corn in such average amounts during such calendar year, he shall proclaim such determination and, commencing with such calendar year, such county shall be included in the commercial corn-producing area. In the case of a county included in the commercial corn-producing area pursuant to this subparagraph, whenever prior to February 1 of any calendar year the Secretary has reason to believe that facts justifying the inclusion of such county are not likely to exist in such calendar year, he shall cause an immediate investigation to be made with respect thereto. If, upon the basis of such investigation, the Secretary finds that such facts are not likely to exist in such calendar year, he shall proclaim such determination, and commencing with such calendar year, such county shall be excluded from the commercial corn-producing area.