| Element/status |
Visual symptoms |
| Nitrogen (N) |
|
| Deficiency |
Light green leaf and plant color with the older leaves turning yellow, leaves that will eventually turn brown and die. Plant growth is slow, plants will be stunted, and will mature early. |
| Excess |
Plants will be dark green in color and new growth will be succulent; susceptible if subjected to disease and insect infestation; and subjected to drought stress, plants will easily lodge. Blossom abortion and lack of fruit set will occur. |
| Ammonium toxicity |
Plants fertilized with ammonium-nitrogen (NH4- N) may exhibit ammonium-toxicity symptoms, with carbohydrate depletion and reduced plant growth. Lesions may occur on plant stems, there may be a downward cupping of the leaves, and a decay of the conductive tissue at the base of the stem with wilting of the plants under moisture stress. Blossom-end rot of fruit will occur and Mg deficiency symptoms may also occur. |
| Phosphorus (P) |
|
| Deficiency |
Plant growth will be slow and stunted, and the older leaves will have a purple coloration, particularly on the underside. |
| Excess |
Phosphorus excess will not have a direct effect on the plant but may show visual deficiencies of Zn, Fe, and Mn. High P may also interfere with the normal Ca nutrition, with typical Ca deficiency symptoms occurring. |
| Potassium (K) |
|
| Deficiency |
On the older leaves, the edges will look burned, a symptom known as scorch. Plants will easily lodge and be sensitive to disease infestation. Fruit and seed production will be impaired and of poor quality. |
| Excess |
Plants will exhibit typical Mg, and possibly Ca deficiency symptoms due to a cation imbalance |
| Calcium (Ca) |
|
| Deficiency |
The growing tips of roots and leaves will turn brown and die. The edges of the leaves will look ragged as the edges of emerging leaves stick together. Fruit quality will be affected with the occurrence of blossom-end rot on fruits. |
| Excess |
Plants may exhibit typical Mg deficiency symptoms, and when in high excess, K deficiency may also occur. |
| Magnesium (Mg) |
|
| Deficiency |
Older leaves will be yellow in color with interveinal chlorosis (yellowing between the veins) symptoms. Plant growth will be slow and some plants may be easily infested by disease. |
| Excess |
Results in a cation imbalance showing signs of either a Ca or K deficiency. |
| Sulfur (S) |
|
| Deficiency |
A general overall light green color of the entire plant with the older leaves being light green to yellow in color as the deficiency intensifies. |
| Excess |
A premature senescence of leaves may occur. |
| Boron (B) |
|
| Deficiency |
Abnormal development of the growing points (meristematic tissue) with the apical growing points eventually becoming stunted and dying. Rowers and fruits will abort. For some grain and fruit crops, yield and quality is significantly reduced. |
| Excess |
Leaf tips and margins will turn brown and die. |
| Chlorine (Cl) |
|
| Deficiency |
Younger leaves will be chlorotic and plants will easily wilt. For wheat, a plant disease will infest the plant when Cl is deficient. |
| Excess |
Premature yellowing of the lower leaves with burning of the leaf margins and tips. Leaf abscission will occur and plants will easily wilt. |
| Copper (Cu) |
|
| Deficiency |
Plant growth will be slow and plants stunted with distortion of the young leaves and death of the growing point. |
| Excess |
An Fe deficiency may be induced with very slow growth. Roots may be stunted. |
| Iron (Fe) |
|
| Deficiency |
Interveinal chlorosis will occur on the emerging and young leaves with eventual bleaching of the new growth. When severe, the entire plant may be light green in color. |
| Excess |
A bronzing of leaves with tiny brown spots on the leaves, a typical symptom frequently occurring with rice. |
| Manganese (Mn) |
|
| Deficiency |
Interveinal chlorosis of young leaves while the leaves and plants remain generally green in color. When severe, the plants will be stunted. |
| Excess |
Older leaves will show brown spots surrounded by a chlorotic zone and circle.
|
| Molybdenum (Mo) |
|
| Deficiency |
Symptoms will frequently appear similar to N deficiency. Older and middle leaves become chlorotic first, and In some instances, leaf margins are rolled and growth and flower formation are restricted. |
| Excess |
Not of common occurrence. |
| Zinc (Zn) |
|
| Deficiency |
Upper leaves will show interveinal chlorosis with an eventual whiting of the affected leaves. Leaves may be small and distorted with a rosette form. |
| Excess |
An Fe deficiency will develop. |
