Cropland Data Layer (CDL) are satellite images depicting agricultural land cover. The images are a useful tool for mo nitoring crop rotation patterns, land use changes, water resources and carbon emissions.

These crop-specific, digital data layers are suitable for use in geographic information systems (GIS) applications. They can be used by agribusinesses, farmers, government agencies, researchers and academic institutions to study pesticide risk, epidemiology, transportation, fertilizer usage, carbon dioxide flux and other topics.

NASS produced the CDLs using satellite images observed at 56-meter (0.775 acres per pixel) resolution and collected from the Resourcesat-1 Advanced Wide Field Sensor (AWiFS), Landsat Thematic Mapper and Moderate Resolution Imaging Spectroradiometer (MODIS). The collection of images was then categorized using on-the-ground farm information including field location, crop type, land cover, elevation, tree canopy and urban infrastructure.

Iowa county CDL maps are available through the links below. The entire inventory of CDL products, including metadata and accuracy assessments, is available online at http://nassgeodata.gmu.edu/CropScape/ .