Fig. 5. Discriminant analysis similarity map determined by discriminant factors F1 and F2 for calibration set of the single-field soil samples, showing Groups 1 (0.0–0.025 kg kg^–1), 5 (0.026–0.075 kg kg^–1), 10 (0.076–0.125 kg kg^–1), 15 (0.126–0.175 kg kg^–1), 20 (0.176–0.225 kg kg^–1), and 25 (0.226–0.275 kg kg^–1).