In this presentation, Dr. Andrew Margenot, associate professor of crop sciences at the University of Illinois Urbana Champaign, shares preliminary findings from ongoing research aimed at updating liming recommendations for Illinois soils.

The presentation revisits long standing assumptions about soil pH, buffer pH, and lime rate recommendations using new laboratory calibrations and on farm trial data. Margenot explains why soil pH alone is not sufficient for determining lime requirements and outlines how reserve acidity is measured through buffer pH tests. Different buffer pH methods and their implications for lime recommendations are reviewed, along with how these approaches compare to current Illinois Agronomy Handbook guidance.