Dave Franzen is a Professor of Soil Science and Extension Soil Specialist with North Dakota State University. He received his BS (1975), MS (1976) and PhD (1993) from the University of Illinois. He worked as agronomist/manager of a chain of fertilizer/ag-chemical retail outlets in central Illinois for about 18 years, and joined NDSU in 1994. His early research focused on soil sampling strategies to direct site-specific nutrient management, but expanded to reconstructing state fertilizer recommendations when the past fertilizer recommendations did not support the new information found from zone/grid soil sampling. His research has spanned corn, soybean, sugarbeet, spring wheat/durum, sunflower and barley, and he has overhauled the fertilizer recommendations for 18 major state crops based on his and other NDSU colleague’s research. The consideration of clay chemistry in formulating potassium recommendation is a first within the USA.