Mineral nutrition seeks to understand the complex interaction between the inorganic and organic: plant life. I enumerate some examples of topics and issues related to the Mineral Nutrition area on interfaces with various knowledge fields that can occur at molecule, cell, tissue, organ, and whole plant level. I try to focus this text on the skills or attributes required to an agronomist in the current "knowledge society". Additionally, I try to point out a current Mineral Nutrition issue dealing with the evaluation and diagnosis of the plant nutritional status, especially towards nitrogen, in real time, an issue that I have focused my latest works. A reasonable knowledge of the plant studied is crucial for diagnosing their mineral deficiencies. Nothing is absolutely right until the diagnosis is proven. The plant nutrient status at sampling, that is, defining whether or not to apply a certain nutrient to the crop at that moment, is possible to be determined by the diagnosis process. The required amount of nutrients for the crop, however, cannot be determined by this process. Procedures are carried out after diagnosis for estimating the fertilizer rate. The actions following diagnosis should be recommendation or prescription of the crop fertilization program followed by this assessment in percentage of correct actions, economic gain and environmental preservation. Such procedures must be performed in a systematic way and coupled to the production system adjusted with the producer.
Agronomist; plant nutrition; diagnosis; action field; skills; abilities; knowledge.