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.