The Secretary of Agriculture is authorized to make a loan or loans for any purpose authorized by and in accordance with the terms of the Bankhead-Jones Farm Tenant Act, as amended, or the Act of August 28, 1937, as amended, to any person eligible for assistance under said Acts who has made or makes a homestead or desertland entry on public land or who has contracted for or contracts for the purchase of other land of the United States in a reclamation project pursuant to the applicable provisions of the homestead and reclamation laws. Any such loans required by the Secretary of Agriculture or by law to be secured by a real-estate mortgage may be secured by a mortgage contract which shall create a lien against the land in favor of the United States acting through the Secretary of Agriculture and any patent thereafter issued shall recite the existence of such lien. The first installment for the repayment of any such loan or any other loan made under the Bankhead-Jones Farm Tenant Act, as amended, or the Act of August 28, 1937, as amended, to the owner of a newly irrigated farm in a reclamation project or to an entryman under the desertland laws, may be deferred for a period of not to exceed two years from the date of the first advance under such loan.