In the 1980s, University of Illinois agronomist John D. Alexander devised a scale to determine a soil’s risk of nitrogen loss. It was based on the characteristics of natural soil drainage class, permeability, slope class, slope configuration, subsoil texture and the amount of warm-season rainfall. Research and observation by Farm Journal Field Agronomist Ken Ferrie suggest Alexander’s rating system is still valid. Click here to attend a FREE webinar with Ken Ferrie.
However, in modern soil surveys, some of the soil characteristics Alexander used are being reported in a different format. Thomas Zerebny of Crop-Tech Consulting has modified Alexander’s scale to fit the format of modern soil surveys. The modified scale can be used as a guideline to evaluate your soils’ potential for nitrogen loss.