Soil Test Methods: A Comparison of Midwest Labs Traditional Methods with Mehlich 3 Extraction

p1, vs, M3 ICP, PhosphorusSoil Test Methods

We compare the P1 Bray Colormetric, Neutral Ammonium Acetate ICP, and DTPA ICP methods to Mehlich III ICP analysis for Phosphorus, Cations (K, Mg, & Ca), and micronutrients (B, Cu, Fe, Mn, & Zn) respectively. The analysis was compared on 664 samples from the Midwest United States and Canada. Correlation of results between methods and relative values are shown.