Comparison of UV, visible and near-infrared, and mid-infrared spectrometers to estimate maize and sorghum leaf nutrients using dry-intact and ground leaves

•Different spectrometers from UV to MIR were compared to estimate plant nutrients.•Regardless of spectral region, models could accurately predict 7 plant nutrients.•Dry ground leaf scans produced the highest accuracies in general.•Dry-intact leaf scans accurately predicted N, P and Mg.•Some portable spectrometer performances were similar to the lab-only instrument.