There are eighteen essential elements for plant nutrition, each with their own functions in the plant, levels of requirement, and characteristics. Nutrient requirements generally increase with the growth of plants, and deficiencies or excesses of nutrients can damage plants by slowing or inhibiting growth and reducing yield. Many deficiencies can be recognized by observing plant leaves. Nutrients that are mobile in the plant will move to new growth areas, so the deficiency symptoms will first show up in older leaves. Nutrients that are not mobile in the plant will not move to new growth areas, so deficiency symptoms will first show up in the new growth.
Mobile nutrients: nitrogen, phosphorus, potassium, magnesium, and molybdenum.
Immobile nutrients: include calcium, sulfur, boron, copper, iron, manganese, and zinc.