A field unit is a group of people who work together to manage a farm or agricultural land. The term can refer to the workers themselves, or to the area of land they are responsible for. ACRE is a unit of measurement for land area, equal to 4, 840 square yards or 0.405 hectares. A BALE is a large bundle of hay, straw, or other material, usually compressed and tied with twine or wire. A SHEAF is a bundle of grain stalks, such as wheat or barley, bound together and typically used for storage or transport. An EAR is the part of a plant that contains the seeds, such as the EAR of corn.