2. Objectives
Know the definition of element, compound,
macronutrient and micronutrient.
Know the 16 essential nutrient elements.
Learn how to use the "Key to Nutrient
Disorders ".
3. Important Definitions
An element is a pure chemical that contains only one type of atom.
A compound is a molecule that contains one or more elements.
“Mineral”: An inorganic element
Acquired mostly in the form of inorganic ions from the
soil
“Nutrient”: A substance needed to survive or necessary for the
synthesis of organic compounds
4. Essential Elements
The 16 elements required by plants are obtained
from the soil, water and air.
Thirteen of these elements must be supplied by the
soil.
Six of the soil elements required by plants are
needed in relatively large amounts and are usually
added to the soil through fertilizer or lime. These
are called macronutrients.
The remaining 7 elements supplied by soil are
required in very small amounts and are termed
micronutrients.
5. Macronutrients
Element Symbol Source
Macronutrients
are needed in Oxygen O Air/Water
relatively large Hydrogen H Air/Water
amounts by Carbon C Air/Water
plants. Nitrogen N Soil
Phosphorus P Soil
Sulfur S Soil
Potassium K Soil
Calcium Ca Soil
Magnesium Mg Soil
6. Macronutrients – Form Used By Plants
Nutrient Form Used
Carbon CO2
Charge on the
Oxygen H2O molecule
Hydrogen H2O
Nitrogen NO3-, NH4+
Phosphorus H2PO4 & HPO42-
Potassium K+
Calcium Ca2+
Magnesium Mg2+
Sulfur SO4-
7. Micronutrients
Macronutrients are Element Symbol Source
needed in Iron Fe Soil
relatively small Manganese Mn Soil
amounts by plants.
Boron B Soil
They are usually
Molybdenum Mo Soil
supplied by
fertilizers. Copper Cu Soil
Zinc Zn Soil
Chlorine Cl Soil
8. Micronutrients – Form Used By
Plants
Nutrient Form Used
Charge on the
Iron Fe2+ molecule
Manganese Mn2+
Boron H2B03-
Molybdenum MoO42-
Copper Cu2+
Zinc Zn2+
Chlorine Cl-
9. Nutrient Deficiency Symptoms
Nutrient deficiency symptoms usually appear
on the plant when one or more nutrients are
in short supply.
In many cases, deficiency may occur
because an added nutrient is not in the form
the plant can use.
Deficiency symptoms for specific elements
are included on the "Key to Nutrient
Disorders".
10. Nutrient Deficiencies
Every soil is not susceptible to the same
nutrient deficiencies.
For example, coarse-textured soils low in
organic matter are susceptible to sulfur
deficiencies whereas sulfur is usually in
adequate supply in clayey soils or soils high
in organic matter.
11. Macronutrient Deficiencies & Soils
Element Soil Factor Causing Deficiency
N&K Excessive leaching on coarse-textured low organic matter soils
P Acid low organic matter soils
Cold wet soils such as occurs during early spring
Newly cleared soils
S Excessive leaching on coarse-textured low organic matter soils
in areas where air pollution is low (minimal levels of SO2 in the
air)
Ca & Mg Excessive leaching on coarse-textured low organic matter soils
Soils where large amounts of K have been applied
12. Micronutrient Deficiencies & Soils
Element Soil Factor Causing Deficiency
Fe Poorly drained soils, Low organic matter soils, pH>7.0, Soils
high in P
Zn Cold wet soils low in organic matter and highly leached, High
pH soils (pH>7.0), Soils high in P, Exposed subsoils
Cu Peat and muck soils, High pH, sandy soils, Soils heavily
fertilized with N
B Excessive leaching on coarse-textured low organic matter soils,
Soils with pH>7.0
Mn Excessive leaching on coarse-textured low organic matter soils,
Soil with pH>6.5
Mo Soils high in Fe oxides, high adsorption of molybdenum, Soil
cropped for a long time
13. Deficiency Symptoms - N
General chlorosis.
Chlorosis progresses
from light green to
yellow.
Entire plant becomes
yellow under prolonged
stress.
Growth is immediately
restricted and plants
soon become spindly
and drop older leaves.
14. Deficiency Symptoms - P
Leaves appear dull,
dark green, blue green,
or red-purple,
especially on the
underside, and
especially at the midrib
and vein.
Petioles may also
exhibit purpling. Re-
striction in growth may
be noticed.
15. Deficiency Symptoms - K
Leaf margins tanned,
scorched, or have necrotic
spots (may be small black
spots which later coalesce).
Margins become brown and
cup downward.
Growth is restricted and die
back may occur.
Mild symptoms appear first
on recently matured leaves.
16. Deficiency Symptoms - Ca
Growing points usually
damaged or dead (die
back).
Margins of leaves
developing from the
growing point are first
to turn brown.
17. Deficiency Symptoms - Mg
Marginal chlorosis or
chlorotic blotches which
later merge.
Leaves show yellow
chlorotic interveinal tissue
on some species, reddish
purple progressing to
necrosis on others.
Younger leaves affected
with continued stress.
Chlorotic areas may
become necrotic, brittle, and
curl upward.
Symptoms usually occur
late in the growing season.
18. Deficiency Symptoms - S
Leaves uniformly light green, followed by
yellowing and poor spindly growth.
Uniform chlorosis does not occur
19. Deficiency Symptoms - Cu
Leaves wilt, become
chlorotic, then necrotic.
Wilting and necrosis
are not dominant
symptoms.
20. Deficiency Symptoms - Fe
Distinct yellow or white
areas appear between
veins, and veins
eventually become
chlorotic.
Symptoms are rare on
mature leaves.
21. Deficiency Symptoms - Mn
Chlorosis is less
marked near veins.
Some mottling occurs
in interveinal areas.
Chlorotic areas
eventually become
brown, transparent, or
necrotic.
Symptoms may appear
later on older leaves.
22. Deficiency Symptoms - Zn
Leaves may be abnormally small and necrotic.
Internodes are shortened.
23. Deficiency Symptoms - B
Young, expanding
leaves may be necrotic
or distorted followed by
death of growing
points.
Internodes may be
short, especially at
shoot terminals.
Stems may be rough,
cracked, or split along
the vascular bundles.
24. Crops Highly Susceptible to Deficiencies
Element Crops
Mn Soybean, Small Grain & Peanuts
Cu Wheat & Corn
Zn Corn
Mo Soybeans & Cauliflower
B Alfalfa, Apples, Peanuts, Tobacco &
Tomatoes
Fe Ornamentals, Fruit Trees, Soybeans, Grain
Sorghum & Some Grasses
