Northwest and Allee Research and Demonstration Farm
Soil moisture samples were taken at eleven sites in northwest Iowa during the last few days of October 2011. Moisture samples were taken at 1-ft increments down to a 5-ft depth. Samples were weighed, oven dried, and reweighed at the ISU Northwest Research Farm. The moisture percentage was calculated from these data, and then used to calculate the inches of plant available moisture in the soil. The data from these sites are listed in the following table.
Iowa State University
DeJong, Joel L. and Kassel, Paul C., "Soil Moisture" (2012). Iowa State Research Farm Progress Reports. 102.