Most of HarvestChoice spatial layers are available for download on our website in ESRI ASCII raster format (with file extension .asc). Just download the layers you need one by one from the "Data & Maps" section at, e.g.

Extract the .asc file from the ZIP archive, and drag and drop it into ArcMap. This should work as shown below (in QGIS). Units and full citation details are available in the README file.