1. Assessment of Soil Testing As It Relates to Corn Ear Leaf Nutrition in the Midwest

Soil testing for P, K and Zn for corn production the Midwest is based on the probability of crop yield response to an applied fertilizer and not on crop nutritional status. Results of three years of observational data from 98 field sites show soil test M3-K only predicted 26% of the variability in ear leaf K at growth stage R1-R2, whereas K base fraction (KBF) predicted 44% of the ear leaf variability and 56% of the variability in the ear leaf K:Mg ratio. Soil M3-P was inconsistent in predicting... R. Miller