Conclusion
A perturbation indicates the change needed, not how to achieve this change. Findings ways to perturb the ionome through a healthy status is a tricky part, where fertilizer trials may become handy. It should be noted that the closest healthy point might not be the easiest to reach, and professional agronomist have a lot of flexibility to constrain their models to local conditions and find a better solution than the closest point. For example, the concentration of aluminium is too high. This could be corrected by increasing the pH of the soil. But in case increasing pH is not a viable solution, the agronomist could look for a high yield zone in the hyper-volume where Al is high, but compensated but a favourable nutrient stauts.
All in all, the approach is fairly simple: