Download Information on symptoms, causes, and solutions

Soil Nutrient Deficiencies: Information on symptoms, causes, and solutions
This table lists the visible symptoms of the main soil nutrient deficiencies you may encounter.
Soil nutrient deficiencies can be difficult to correctly diagnose. We suggest that you consult with
other farmers, your local agricultural extension officer, or scientists at Rocks for Crops or ICRAF
before you treat the deficiency. Ask these people about timing, amount, and placement of
fertilizers.
Visible Symptoms
Macronutrients
The old leaves at bottom of the plant
turn yellow. The yellow starts at the tip
of the leaf and spreads up the middle of
the leaf.
Probable
Cause
Methods to Treat the Deficiency
Nitrogen
deficiency
- Grow nitrogen fixing crops (e.g. lablab,
mucuna)
- Grow Tithonia hedges and use cuttings as a
green manure mulch
- Intercrop with legumes such as pigeon pea,
mucuna or crotalaria or trees like Sesbania
sesban or Leucaena
- Add animal or green manure
- Add fertilizers with ingredients like
ammonium or nitrate. Commonly used
fertilizers are DAP (diammonium phosphate),
urea, or top- and side-dressing with CAN
(calcium ammonium phosphate)
- Add phosphate or ‘bone’ fertilizer. A
commonly used fertilizer is DAP
(diammonium phosphate)
- Add phosphate rocks (PR)
- Add PR and grow Tithonia hedges on the PR.
Use Tithonia cuttings as a green manure mulch
Leaves are small and light green. The
lower, older leaves are lighter in colour
than the top, younger leaves.
The stalks or stems are weak. Plants
are smaller than normal.
The leaves are reddish-purple at the
edges. The colour is most notable in
young plants.
Phosphorus
deficiency
The leaves are darker green than normal
and the leaf tips may look burnt.
Sometimes there is yellow between the
veins of the bottom leaves.
The plants are smaller than normal and
their growth is stunted.
The old, bottom leaves wilt and turn
yellow starting at the tips and edges.
There are dead areas around the tips and
margins of the lower leaves or the
leaves are mottled.
The plants grow slowly and the stalks
or stems are weak.
Potassium
deficiency
- Add potassium rich volcanic rocks or
‘potash’ fertilizer. A commonly used fertilizer
is MOP (muriate of potash)
- Add wood ash
Visible Symptoms
Probable
Cause
Methods to Treat the
Deficiency
Many of the leaves are irregularly shaped. Some leaf
tips are hooked-shaped or cup-shaped. The tips of
new leaves often are attached to the leaves below.
The leaves may be crinkled.
Calcium
deficiency
(this is a
difficult
deficiency to
identify)
- Add limestone, dolomite or
gypsum
- Add a calcium fertilizer
Magnesium
deficiency
- Add magnesium
- Ensure there’s enough
calcium in the soil (without
enough calcium, magnesium
may be leached from the soil)
- Add dolomite, vermiculite
Sulphur
deficiency
- Add sulfur from volcanic
sources (if available)
- Add gypsum
- Add organic matter as
compost or green manure
The problems are noticeable first on older tissue.
Nitrogen,
phosphorus or
potassium
deficiency
The problems are noticeable first on younger tissue.
Calcium or
boron
deficiency
- Nitrogen, phosphorus and
potassium are mobile plant
nutrients that move from
places where they are stored to
places where they are needed
- Add nitrogen, phosphorus or
potassium
- Calcium and boron are
immobile plant nutrients that
do not move from old leaves
to new leaves
- Add extra calcium or boron
The tip of the shoot is dying and ends of young
leaves are dying.
Fruits rot at the blossom end.
There is striping along the older leaves. This striping
may spread to all the leaves. The leaves appear
striped because there is yellow between the veins
while the veins remain green. After striping appears,
dead round spots on the leaves may follow. The
spots often look like disease symptoms.
The leaf edges may curl up or down and leaves may
die later.
The top, younger leaves are light green or yellow.
Eventually, the entire plant becomes pale green or
yellow. The leaf veins may have a lighter colour
than the areas between the veins.
Over time, the leaves may shrivel, but the tip of the
shoot will remain alive.
The symptoms may often look like they are caused
by a nitrogen deficiency, but they start with the
young leaves when it is a sulphur deficiency.
Visible Symptoms
Probable
Cause
Micronutrients – these deficiencies are often difficult to identify
The older leaves turn yellow and die at the edges. There is Molybdenum
a general yellowing of the older leaves with the main veins deficiency
turning yellow. The rest of the plant often becomes light
green.
The growth is stunted and the leaves decrease in size. In
some plant species, the leaves are irregularly shaped.
There are white or pale yellow bands between the veins of
the new leaves. The growing top bud of the plant also is
turning white.
Methods to Treat the
Deficiency
- Add a fertilizer with
ingredient names like
molybdate
- Increase the soil pH
- Spray the leaves with a
solution containing
molybdenum compounds
Zinc
deficiency
- Add zinc compounds
- Make sure the soil has
enough phosphorus
because plants use zinc
and phosphates together
The young leaves are pale. The veins remain green and
there is yellow between the veins of the new leaves. The
edges and tips of the leaves may start to die.
Iron deficiency
- Add a fertilizer with
iron or iron chelate
The symptoms appear on the new leaves first. There is
yellow between the green veins on the young leaves. The
symptom is similar to iron, but the striping is not as pale
yellow as in the iron deficiency. The symptoms are also
similar to magnesium, but magnesium symptoms appear on
the old leaves first.
Manganese
deficiency
- Add a fertilizer with
ingredient names like
manganese
Copper
deficiency
- Add a fertilizer with
ingredient names like
copper, cupric or cuprous
At the top of the plant, the distances between leaves are
shorter than normal.
The leaves have greenish-grey or dead spots.
The leaves are darker green than normal.
The plant growth is stunted. The young leaves have
irregular shapes. The tips of the leaves are pale in colour.
The plants may not flower. Many leaves fall off the plant.
Visible Symptoms
Probable Cause
Methods to Treat
the Deficiency
The plant is not growing normally. The tip of the
shoot is dying and buds and flowers are falling
off.
Boron deficiency
- Add a fertilizer with
ingredient names like
borax or borate
The leaves are curled, and grayish-green in
colour.
Drought
- Grow drought
resistant crops such as
millet or cassava
- Add water
There are small spots on leaves. These spots
gradually spread over leaf.
The leaf tips and edges are burnt. The leaf looks
like it is dying.
Disease: blight, insects
The stems and stalks are fatter than normal and
break easily. The spaces between leaves are
shorter than normal.
Sometimes, the young leaves are discoloured and
may die. Other times, the older leaves may be
yellow between the veins. Some leaves have
small dead spots.
Symptoms Caused by Other Factors
Chemical burn
- Apply fertilizers
correctly and at proper
distance from seeds
- Use organic or rock
alternatives
- Reduce or stop
spraying chemicals if
possible