Updated: Sep 6, 2018
In the soil, nutrients interact with one another leading to changes in availability to plants. The figure below (Mulder's Chart) displays the various interactions that can occur.
Antagonism: High levels of a particular nutrient in the soil can interfere with the availability and uptake of other nutrients. For example, high nitrogen levels can reduce the availability of boron, potash and copper; high phosphate levels can influence the uptake of iron, calcium, potash, copper and zinc; high potash levels can reduce the availability of magnesium. Thus, the application of high levels of nitrogen, phosphorus and potassium can induce plant deficiencies of other essential elements.
Stimulation: This occurs when the high level of a particular nutrient increases the demand by the plant for another nutrient. For example, increased nitrogen levels create a demand for more magnesium.