N.C. Gen. Stat. § 115C-264.4

A local school board may develop and implement policies and procedures to facilitate and maximize to the extent practicable, purchases of food grown or raised in North Carolina, including, but not limited to, policies that permit a percentage price preference for the purpose of procuring food grown or raised within the State. As used in this section, "price percentage preference" means the percent by which a responsive bid from a responsible bidder whose product is grown or raised in North Carolina may exceed the lowest responsive bid submitted by a responsible bidder whose product is not grown or raised in North Carolina.