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Soil
Fertility
Components of Functional Soils
Terms and definitions
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Essential Nutrient:
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Deficiency:
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Element necessary for plant growth and reproduction. For
example: nitrogen, phosphorus, and potassium.
Plant condition where an essential nutrient is not
sufficiently available.
Symptom:
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A visual sign or condition that results from a deficiency:
symptoms aid in diagnosing a deficiency.
Terms and Definitions (Cont.)
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Fertilizer:
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Natural, manufactured, or processed material or
mixture of materials that contains one or more of
the essential nutrients; available in:
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dry form
liquid form
gaseous form
Fertilizer Terms
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Analysis:
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Sources of Nutrients:
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Percentage water soluble content of nitrogen (N),
phosphorus (P), and potassium (K) in the fertilizer.
N: Ammonia (NH4); P: (MgPO4) or any other phosphate;
K: Potash (K2CO3)
Complete Fertilizer:
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Fertilizer which supplies all three primary nutrients,
(N,P,K)
Chemical Elements Essential To
Plant Growth
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Non-mineral (sourced
from air and water)
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Carbon (C)
Hydrogen (H)
Oxygen (O)
Nitrogen (N)
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Mineral (sourced from the
soil)
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Primary
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Secondary
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Nitrogen (N)
Phosphorus (P)
Potassium (K)
Calcium (Ca)
Magnesium (Mg)
Sulfur (S)
Micronutrients
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Iron (Fe), Boron (B), Manganese
(Mn), Copper (Cu), Zinc (Zn),
Molybdenum (Mo), Chlorine (Cl),
Lead (Pb), Mercury (Hg), etc.
10 Essential Elements
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Essential Elements
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Carbon (C)
Hydrogen (H)
Oxygen (O)
Phosphorus (P)
Potash (K)
Nitrogen (N)
Sulfur (S)
Calcium (Ca)
Iron (Fe)
Magnesium (Mg)
C. HOPKNS CaFé
Mighty good
Functions of Nutrients for
plant growth
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Carbon, Hydrogen, and Oxygen are needed in
the plant processes of photosynthesis and
respiration.
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Approximately 95% of the weight of plants
comes from products of photosynthesis
Primary Nutrient Functions
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Nitrogen (N)
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Gives green color to plant
Induces vigorous , rapid growth in plants
Increases protein and yield
Aids and promotes seed and fruit development
Plants cannot utilize N as a gas, it must be
combined with other elements.
More Primary Nutrient
Functions
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Phosphorus (P)
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Important to germinating seedlings
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Contributes to early maturing crops
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Necessary for seed and fruit formation
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Stimulates root growth
Primary Nutrient Functions
(Cont.)
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Potassium (K)
 Controls water intake and respiration
 Necessary for production and translocation
(“positioning”) of carbohydrates
 Produces plumper seeds
 Stiffens straw and stalks
Secondary Nutrient Functions
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Sulfur (S)
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Necessary for nodule formation on legumes
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Associated with plant enzyme systems
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Stimulates seed production
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Affects protein and crop quality
Secondary Nutrient Functions
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Calcium (Ca)
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Promotes root and leaf growth
Speeds decay of organic matter
Stimulates formation of nitrates
Necessary for nodulation of legumes
Secondary Nutrient Functions
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Magnesium (Mg)
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Aids in the formations of fats and oils
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Necessary for chlorophyll or green plant color
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Increases adsorption of phosphorus
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Important in plant enzyme system
Primary nutrient deficiency
symptoms
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Nitrogen (N)
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Stunted and Spindly
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Yellow, yellowish green or light green in color in
foliage (chlorosis)
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Older leaves affected first, starting at the tip and
moves along the middle of the leaf.
Primary nutrient deficiency
symptoms (Cont.)
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Phosphorus (P)
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Purple leaves or portions of leaves in advanced
stages
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Stunted Growth
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Very dark green color
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Older leaves affected first
Phosphorus Deficiency
Primary nutrient deficiency
symptoms (Cont.)
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Potassium (K)
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Lodging (bending of the stem) occurs
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Shorter plants
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Bronzing or browning of leaf color
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Leaves show yellow to brown coloring along leaf
margins followed by complete browning.
Potassium Deficiency
Secondary nutrient deficiency
symptoms
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Sulfur (S)
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Young plants have stunted appearance
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Leaves have a light-green to yellow coloring
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Stems are thin and spindly
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Sulfur deficiency symptoms are similar in
appearance to nitrogen deficiency symptoms.
Secondary nutrient deficiency
symptoms
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Magnesium (Mg)
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Leaf tissue becomes yellow, veins remain green
(interveinal chlorosis)
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Leaf parts between veins show a whitish color
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Leaves curl upward along the margins
Deficiency By Other Means
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Other conditions besides deficiencies
may cause abnormal plant growth.
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Cold, wet weather, lack of sunlight, disease,
insect damage, and improperly applied
chemicals are examples.