12 U.S.C. § 2016

(a) In general Loans and discounts made by a Farm Credit Bank shall bear such rate or rates of interest or discount, and be on such terms and conditions, as may be determined by the board of directors of the bank from time to time. (b) Setting rates and charges In setting rates and charges, it shall be the objective to provide the types of credit needed by eligible borrowers at the lowest reasonable costs on a sound business basis taking into consideration the cost of money to the bank, necessary reserve and expenses of the bank and associations, and providing services to members. The loan documents or discounting and financing agreements, may provide for the interest rate or rates to vary from time to time during the repayment period of the loan or agreement.