A good plant nutrition is the correct synergy of different nutrients. No nutrient should be in abundance and no nutrient should be in deficiency.
A nutrient surplus is always questionable if:

•     is absorbed preferentially or passively with the water flow, thus creating an imbalance in the plant,
•     displaces another nutrient through overconcentration in the soil solution or at the sorption complex and this nutrient is then deficient in the plant,
•     can be washed away or
•     simply costs money and thus causes unnecessary costs.

In this respect, each nutrient and each situation must be considered individually from the point of view of soil science and plant nutrition. A certain surplus of nutrients can - but does not always have to - be a cause for concern. A nutrient deficiency, on the other hand, is always negative for plant growth. Liebig's Growth Tone has been illustrating this for decades. The nutrient deficiency has been recognized and quantified as such because the plants have lagged behind in growth.
  
Now if we dismiss nitrogen and the trace elements, an interesting picture emerges for the basic nutrients (pH, Ca, P, K, Mg). For this purpose, we have evaluated all soil sampling results (almost 300,000 analyses) from the last four years. The aim was to answer the question of whether one or more of these four basic nutrients are deficient or not. Each sample was counted only once. The lowest content class of one of the four nutrients thus defines the assignment to a group: