Looking at the micro and macro nutrients in soil and crop vocabularies seem to have some limited ranges. Particularly for nitrogen (N) these are in the lower range (1000 mg/kg) of what I have seen in some literature... See a couple links:

1. https://doi.org/10.1016/j.heliyon.2023.e17321
2. https://doi.org/10.3390/rs12071139

This is probably a compromise for different crops, which probably have different ranges of (micro-) nutrients and the check will happen across all crops. Perhaps the ranges for the different parts (grain, leaf, etc) could also be moved to the crops specific vocabulary (same as for yield)?

@rhijmans @celineaubert @cedricngakou