Banks authorized to make commodity loans.

(1) Banks may make loans known and described as “commodity loans” on the obligations of any person, firm, copartnership, association, or corporation, in the form of notes or drafts secured by shipping documents, warehouse receipts, or other such documents transferring or securing title covering readily marketable nonperishable staples when such property is fully covered by insurance if it is customary to insure such staples, in the following percentages of the capital accounts of the bank:

(a) Twenty-five percent, when the market value of such staples securing such obligation is not at any time less than 115 percent of the face amount of such obligation.

(b) Thirty percent, when the market value of such staples securing such obligation is not at any time less than 120 percent of the face amount of such obligation.

(c) Thirty-five percent, when the market value of such staples securing such obligation is not at any time less than 125 percent of the face amount of such obligation.

(d) Forty percent, when the market value of such staples securing such obligation is not at any time less than 130 percent of the face amount of such obligation.

(e) Forty-five percent, when the market value of such staples securing such obligation is not at any time less than 135 percent of the face amount of such obligation.

(f) Fifty percent, when the market value of such staples securing such obligation is not at any time less than 140 percent of the face amount of such obligation.

(2) The increased loan limitation provided by this section shall not apply to obligations of any one person, firm, copartnership, association, or corporation arising from the same transaction or secured upon the identical staples for more than 10 months.