Upon termination of any marketing program, all remaining unobligated funds shall be refunded on a pro rata basis to the persons from whom the funds were collected in the preceding 2 years. If the program operating board finds that the amounts refundable are so small as to make refunding impracticable, the funds may be used to defray expenses incurred by the Department in the development, adoption and administration of any subsequent marketing program for soybeans. If not utilized within a period of 2 years after termination of the marketing program, such funds shall be deposited into the General Revenue Fund of the State Treasury.