When you take out those loans (or about any loan for that matter) you sign a UCC (Uniform Commercial Code) form granting the lender first lien on the commodity or collateral.  The UCC is filed at the Secretary of State's office and is effective for 5 years, unless the lender files a release sooner than that.  It generally isn't automatic, you have to request your lender to release the lien.  FSA or CCC just leaves the UCC filing in place when one loan is paid off in case a borrower requests a new loan within that 5 year time frame.  If the original loan is longer than 5 years in term, a UCC renewal must be filed before the initial one expires.