Abstract: Imagery-based boundary identification for agricultural fields is provided. In various embodiments, a time series of surface reflectance rasters for a geographic region is received. For each of the surface reflectance rasters, at least one index raster is determined, yielding at least one time series of index rasters. The at least one time series of index rasters is divided into a plurality of consecutive time windows. The at least one time series of index rasters is composited within each of the plurality of time windows, yielding a composite index raster for each of the at least one time series of index rasters in each of the plurality of time windows. The composite index rasters are segmented into a plurality of spatially compact regions of the geographic region. A plurality of polygons is generated from the plurality of spatially compact regions, each of the plurality of polygons corresponding to an agricultural field in the geographic region.