Agricultural land. Land that is a part of a farm unit actively engaged in the commercial production or growing of crops, plants, or animals under a sound management program. Agricultural land includes woodland and wasteland that is a part of the farm unit, but the woodland and wasteland included in the unit must be appraised under the use‑value schedules as woodland or wasteland. A farm unit may consist of more than one tract of agricultural land, but at least one of the tracts must meet the requirements in G.S. 105‑277.3(a)(1), and each tract must be under a sound management program. If the agricultural land includes less than 20 acres of woodland, then the woodland portion is not required to be under a sound management program. Also, woodland is not required to be under a sound management program if it is determined that the highest and best use of the woodland is to diminish wind erosion of adjacent agricultural land, protect water quality of adjacent agricultural land, or serve as buffers for adjacent livestock or poultry operations.