NASA published a blog post on a set of soil composition maps this week, which really show the range of water-holding capacity across the United States.  The series of maps show the composition of soil by sand, clay, and silt as well as showing the available water storage.  As expected, the water storage of Southeastern soils is not large, which means that ample rainfall or irrigation is critical in maintaining the growth of crops.  It is fascinating to see how the composition varies across the country.

You can see the maps and read about it at https://earthobservatory.nasa.gov/IOTD/view.php?id=87220

water storage conus_gis_1998