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NUTRIENT |
FUNCTION |
SYMPTOMS OF DEFICIENCY |
SUSCEPTIBLE SPECIES |
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Nitrogen (N) |
Nitrogen is
the most critical nutrient for optimum farm production.
Since it is readily leached from the soil, its level
in soil is typically low, however the levels required for
optimum crop growth are quite high and thus generous
application is typically required. Nitrogen is a primary
constituent of protein and chlorophyll. A shortage of
Nitrogen reduces all aspects of crop and pasture production
e.g. growth, yield and quality. |
Plants, which
have Nitrogen for only limited growth, may exhibit chlorosis
especially in the older leaves. In severe case, the leaves
first yellow and then tan as they die. Some plants
(tomatoes, maize) may exhibit a purplish coloration of the
stems, petioles and on the underside of their leaves.
|
All Plants. |
|
Phosphorous (P) |
Phosphorous is an essential element
for cell division and growth. It is required for
photosynthesis, sugar and starch production, energy transfer
and the movement of carbohydrates within the plant and
reproduction. |
Plants
exhibit stunted growth and leaves are often dark green in
colour. Oldest leaves become dark brown as they die.
Maturity may be delayed. |
All Plants. |
|
Potassium (K) |
Potassium is
an essential element for protein, carbohydrate and fat
synthesis and is required for the proper functioning of
chlorophyll and other enzymes involved in photosynthesis,
respiration and protein formation. It is essential for cell
division, cell electrolyte balance and for the functioning
of plant stomates. |
Crops
suffering this deficiency appear scorched around the edges
and the surfaces are irregularly chlorotic. In legumes, the
chlorotic spots form patterns around the leaf edges. Cereal
grains develop weak stalks and their roots may become more
prone to infection by root rotting organisms. These two
factors may result in collapse of the crop by wind or rain. |
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|
Iron (Fe) |
Iron is an essential element required
for the synthesis of chlorophyll. It is involved in the
activation of many enzymes used in photosynthesis and
respiration. In animals, iron is a key constituent of
hemoglobin, the species that carries oxygen in the blood.
Iron is relatively
immobile and is generally in short supply in alkaline soils. |
Young leaves develop chlorosis in the
interveinal areas which may develop into white leaves with
necrotic spots. Stunted growth.
In animals, iron
deficiency results in anaemia, wasting and eventual death. |
Roses, shrubs, fruit trees, maize,
sorghum, peas, tomatoes and cereals. |
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Sulphur (S) |
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Manganese (Mn) |
Manganese is an essential nutrient for the growth of both
plants and animals. In plants it enhances root growth,
disease resistance and the development of fruit. It is
required for the synthesis of chlorophyll and
assimilation of nitrate. It is involved in the activation of
many enzymes involved in photosynthesis and respiration. In
animals, manganese is essential for growth, reproduction,
skeletal growth and carbohydrate metabolism. |
Symptoms vary with species; in cereals
– grey – white spots, flecks and stripes may appear in the
interveinal areas. In legumes, interveinal chlorosis of
young and middle aged leaves and tissue may rapidly become
necrotic. Seed disorders e.g. "split seed" or "marsh spot"
may develop.
In animals,
deficiency may result in malformed bones with enlarged
joints and may affect the reproductive cycle e.g. fertility. |
Beans, Lettuce, Oats, Onion, Peas,
Potatoes, Radish, Sorghum, Spinach and Wheat. |
|
Boron (B) |
Boron is an essential element in plant
nutrition. It is essential for root tip, pollen tube and
shoot growth and the synthesis of DNA and RNA. |
Leaf blades
may be distorted and stems may become brittle and crack e.g.
"stem crack" in celery. Shorter internodal length, retarded
growth or necrosis of the terminal buds and youngest leaves.
Reduction or failure to seed and fruit. Malformation of
fruit. |
Lucerne, Clovers, Citrus and
Vegetables (especially tubers). |
|
Zinc (Zn) |
Zinc is an
essential nutrient required for the functioning of a large
number of enzymes involved in the growth and reproduction of
both plants and animals. It is required for the synthesis
and functioning of chlorophyll, is involved in the plant
hormone system and acts as a catalyst for the plant growth
regulator, auxin. |
In plants, shortened internodes with
excessive branching (rosetting) of small, dark green
deformed leaves. In cereals and grasses – chlorotic bands
(yellow, red) may appear either across or within the veins.
Stunted growth and necrosis of older leaves.
In animals, crusty
growths, cracking of skin and loss of hair. |
Barley, Onions, Beans, Maize, Sorghum
and Citrus Fruit. |
|
Copper (Cu) |
Copper is an essential nutrient
required for the functioning of several enzymes associated
with plant growth. It enhances photosynthesis thereby
increasing the digestible energy in plant species, and
enhances nodulation in legumes, resulting in increased
nitrogen fixation. Copper is also involved with the
production of lignin for cell walls and in seed and fruit
development.
In animals, copper
is required for pigmentation, myelination of nerve fibres,
blood synthesis, bone development, body and wool growth as
well as playing a part in reproduction and lactation. Copper
also enhances the disease resistance of plants and animals. |
Young leaves become dark green,
twisted and deformed. Necrotic spots may appear. In grains
and grasses, seed production is reduced and seed heads may
be white and empty.
Deficiency in
animals may include reduced milk production, infertility,
skeletal defects and bone fragility, anaemia, cardiovascular
diseases in cattle, rough coats or hair abnormalities e.g.
"steely wool" in sheep, "swayback" in lambs and "ill-thrift"
in cattle.
|
Small grains, Maize, Vegetables,
Sorghum, Fruit Trees, Ornamentals, Wheat, Carrots and
Onions.
Sheep, Lambs, Cattle and Dairy. |
|
Molybdenum (Mo) |
Molybdenum is
an essential element for both plants and animals. In plants,
Molybdenum is required for protein synthesis. It enhances
both photosynthesis in plants and nitrogen fixation in
legumes. In animals, Molybdenum is a constituent of several
important enzymes, and plays a role in animal fertility, the
estrus cycle, and mammary anti-carcinogenesis. |
In plants, reduced and irregular leaf
blade formation, interveinal mottling and chlorosis around
the edges of older leaves. Necrotic spots at leaf tips and
edges, smaller root nodules coloured white or green (not
pink), growth inhibition in legumes.
Lower reproduction
rates in animals. |
Oats, Legumes, Radish, Sorghum, Wheat,
Onion, Lettuce, Cauliflower and Broccoli. |
|
Cobalt (Co) |
Cobalt is a
key constituent of Vitamin B12 and Propionate (the major
source of energy in ruminants). Cobalt enhances the nitrogen
fixing ability of legumes and improves the efficiency of
ruminal digestion. |
Small root nodules on legume species.
Uniformly pale green – yellow leaves, most severe on old
leaves. Some crops may develop red leaves, stems or
petioles. Stunted growth – tops may be less leafy. Grain or
seed production may be retarded.
In animals, loss of
appetite, body weight, (emaciation), anaemia, poor growth of
heifers, weeping eyes, decreased milk production and white
liver disease and salt stick. |
Clover, Lucerne and other Legumes. |
|
Selenium (Se) |
Selenium is an essential nutrient for
animals, but not plants. It is involved in the production of
antibodies and in the elimination of unwanted microorganisms
and thus plays an important role in disease resistance. It
prevents white muscle disease in livestock, exudative
diathesis in poultry and liver necrosis in pigs. |
White muscle disease, ill-thrift,
stiff lamb disease, infertility and embryonic mortality. |
Lambs, Calves, Poultry and Pigs. |
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Calcium (Ca) |
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Magnesium (Mg) |
Magnesium is an essential nutrient for
the synthesis of chlorophyll. It is involved with the
functioning of several enzymes associated with
photosynthesis, respiration and reproduction. |
Interveinal
chlorosis of older leaves. |
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