Macronutrients 

The availability of mineral elements may cause symptoms on potato plants that are associated with either a deficiency or an excess (phytotoxicity) of certain nutrients.

Symptoms of deficiency are observed chiefly in filtering or sandy soils, which are prone to severe leaching, or in certain countries where crops are grown in pure sand and are fertigated.

The deficiency may be due to an insufficient supply of certain nutrients or because their availability is reduced by another factor (pH, chemical balance between elements, etc.).

The symptoms described in this chapter are given as a guideline and the confirmation of a deficiency or of an excess of nutrients usually requires further plant and/or soil analysis in a laboratory.