Western Research and Demonstration Farm
Each spring and fall, a soil moisture survey is conducted to determine the amount of plant-available water (PAW) in the top five feet of the major soils in Iowa. Adequate soil moisture reserves increase the probability of average or above-average crop yields in the following season. Producers may use this information to alter their crop management plans according to expected soil moisture levels. Several sampling sites are located at the Western Research and Demonstration Farm.
Iowa State University
Vagts, Todd, "Subsoil Moisture Levels for 2004" (2005). Iowa State Research Farm Progress Reports. 1300.