Segment Boundaries
lJune Agricultural Survey (JAS) segments
–Enumerator records field extents, cover types, and acreage
•Every June, approximately 41,000 farms are visited or called by enumerators as part of the June Agricultural Survey.  States that participate in the Cropland Data Layer Program will have every field digitized by the NASS field office staff or cooperating partners.
•The unit of observation is the tract, which may contain one or more fields or land uses and represents a particular land operator’s acreage within a segment.  The enumerators draws off field boundaries onto the National Aerial Photography Program’s (NAPP) 1:8,000 scale black and white aerial photos where the segment is located, according to their observations and the farmer reported information.  The fields are labeled and the cover type is recorded using a grease pencil on the aerial photo.
•Enumerators account for every field/land use type within a segment.  They assign each field a cover type based upon a fixed set of land use classes for each state.  Every field within a segment must fit into one of the pre-defined classes.