Nutrient Deficiency

Potash

Insufficient plant-available potash in the soil often manifests itself first as a blue-green colouration of the leaf. As the deficiency becomes more acute, the leaf colour can change from dark-green to a typical violet, brownish-red or brown. These discoloured areas appear first at the leaf-margin and then spread towards the centre. In fruit crops, fewer and smaller fruits are produced. 

Phosphate

Phosphate deficiency is most common in areas of high rainfall, especially on acid, clay or chalk soils. Symptoms include poor growth and leaves that turn blue-green but not yellow. The oldest leaves are affected first.

Magnesium

Magnesium deficiency occurs most often in strongly acidic, light, sandy soils where magnesium can be easily leached away. Without magnesium, plants begin to degrade the chlorophyll in older leaves, impeding photosynthesis and normal plant growth. Plants will have yellowing between leaf veins. The veins stay green, giving the leaves a marbled appearance.

Sulphur

Sulphur deficiency looks very similar to magnesium deficiency but differs in a crucial respect: in sulphur deficiency the younger leaves first exhibit yellowing at the edges and between veins whereas in magnesium deficiency older leaves are affected first.

Manganese

Manganese deficiency is the most common trace element deficiency in England and Wales. Crop failure can occur without treatment. The most severe problems occur on black sands and organic or peaty soils with a pH above 6.0. Deficiency is common but less severe on sands and loamy sands with a pH above 6.5. Over-liming frequently induces manganese deficiency. Symptoms may be transient and can disappear following rain.

Copper

Since copper is relatively immobile in plant tissue, deficiency symptoms tend to appear initially in young tissues. Severely affected cereals show pale green young leaves that may become twisted and whitened. Ears may be malformed with full grains at the base, shriveled grain in the middle and none at all towards the tip. In sugar beet, young leaves become a darker blue-green while older leaves show white tips.

Boron

The role of boron in plant metabolism includes maintenance of cell membranes and transport of other nutrients through them. When boron is deficient, plant tissue at growing points becomes distorted and eventually dies. This can lead to loss of apical dominance, development of side shoots and a bushy appearance to the plant. Deficiency also affects pollination and seed set. A large proportion of hollow hulls in sunflower is a typical symptom of boron deficiency. Damage to cell walls is responsible for the brown flecks, stripes and zones associated with boron deficiency in sugar beet (‘heartrot’), swedes (‘brown rot’), carrots (‘five o’clock shadow’) and celery (stripes along stems).

Calcium

Acidic, sandy or coarse soils often contain less calcium. Even when there is a lot of calcium in the soil, there can still be deficiency if it is in an insoluble that is unusable by the plant. Soils containing high phosphorus are particularly susceptible to creating insoluble forms of calcium.