Soil Fertility

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Soil Fertility

• Original by Andrew Laca
• Modified by Georgia Agricultural Education
  Curriculum Office
• July, 2002

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Terms and definitions

• Essential Nutrient- Element necessary for plant
  growth and reproduction, for example nitrogen,
  phosphorus, and potassium.
• Deficiency- Plant condition where an essential
  nutrient is not sufficiently available.
• Symptom- A visual sign or condition that results
  from a deficiency symptoms aids in diagnosing a
  deficiency.

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More Terms and Definitions

• Fertilizer- Natural, manufactured, or processed
  material or mixture of materials that contains
  one or more of the essential nutrients available
  in
• dry form
• liquid form
• gaseous form

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Fertilizer Terms

• Analysis- Percentage water soluble content of
  nitrogen (N), phosphorus (P) expressed as P2O5,
  and potassium (K) expressed as K2O in the
  fertilizer.
• Brand- Trademark of the company which produced
  the fertilizer.
• Complete Fertilizer- Fertilizer which supplies
  all three primary nutrients, (N,P,K)

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Chemical Elements Essential To Plant Growth

• Non-mineral- air and water
• Carbon (C)
• Hydrogen (H)
• Oxygen (O)
• Nitrogen (N)

• Mineral- from the soil
• Primary
• Nitrogen (N)
• Phosphorus (P)
• Potassium (K)
• Secondary
• Calcium (Ca)
• Magnesium (Mg)
• Sulfur (S)
• Micronutrients
• Iron (Fe), Boron (B), Manganese (Mn), Copper
  (Cu), Zinc (Zn), Molybdenum (Mo), Clorine (Cl)

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10 Essential Elements

• Essential Elements
• Carbon (C)
• Hydrogen (H)
• Oxygen (O)
• Phosphorus (P)
• Potash (K)
• Nitrogen (N)
• Sulfur (S)
• Calcium (Ca)
• Iron (Fe)
• Magnesium (Mg)

C. HOPKINS CAFÉ Mighty Good
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Functions of Nutrients for plant growth

• Carbon, Hydrogen, and oxygen are needed in the
  plant processes of photosynthesis of
  photosynthesis and respiration.
• Approximately 95 of weight of plants comes from
  products of photosynthesis

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Primary Nutrient Functions

• Nitrogen (N)
• Gives green color to plant
• Induces vigorous , rapid growth in plants
• Increases protein and yield
• Aids and promotes seed and fruit development
• Nitrogen constitutes 80 of the atmosphere, yet
  it is one of the most critical elements for plant
  growth.
• Plants cannot utilize N as a gas, it must be
  combined with other elements.

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More Primary Nutrient Functions

• Phosphorus (P)
• Important to germinating seedlings
• Contributes to early maturing crops
• Necessary for seed and fruit formation
• Stimulates root growth

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Primary Nutrient Functions Cont.

• Potassium (K)
• Necessary for production and translocation of
  carbohydrates
• Produces plumper seeds
• Controls Water intake and respiration
• Stiffens straw and stalks

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Secondary Nutrient Functions

• Sulfur (S)
• Necessary for nodule formation on legumes
• Associated with plant enzyme systems
• Stimulates seed production
• Affects protein and crop quality

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Secondary Nutrient Functions

• Calcium (Ca)
• Speeds decay of organic matter
• Stimulates formation of nitrates
• Promotes root and leaf growth
• Necessary for nodulation of legumes

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Secondary Nutrient Functions

• Magnesium (Mg)
• Necessary for chlorophyll or green plant color
• Increases adsorption of phosphorus
• Aids in the formations of fats and oils
• Important in plant enzyme system

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Symptoms of nutrient deficiencies

• Review
• Deficiency- Plant condition where an essential
  nutrient is not sufficiently available.
• Symptom- A visual sign or condition that results
  from a deficiency symptoms aids in diagnosing a
  deficiency.

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Primary nutrient deficiency symptoms

• Nitrogen (N)
• Stunted and Spindly
• Yellow, yellowish green or light green in color
  in foliage (chlorosis)
• Older leaves affected first, starting at the tip
  and moves along the middle of the leaf.

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Primary nutrient deficiency symptoms

• Phosphorus (P)
• Stunted Growth
• Very dark green color
• Purple leaves or portions of leaves in advanced
  stages
• Older leaves affected first

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Phosphorus Deficiency
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Primary nutrient deficiency symptoms

• Potassium (K)
• Shorter plants
• Bronzing or browning of leaf color
• Lodging (bending of the stem) occurs
• Leaves show yellow to brown coloring along leaf
  margins followed by complete browning.

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Potassium Deficiency
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Secondary nutrient deficiency symptoms

• Sulfur (S)
• Young plants have stunted appearance
• Leaves have a light-green to yellow coloring
• Stems are thin and spindly
• Sulfur deficiency symptoms are similar in
  appearance to nitrogen deficiency symptoms.

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Secondary nutrient deficiency symptoms

• Magnesium (Mg)
• Leaf parts between veins show a whitish color
• Leaf tissue becomes yellow, veins remain green
  (interveinal chlorosis)
• Leaves curl upward along the margins

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Deficiency Continued

• Other conditions besides deficiencies may cause
  abnormal plant growth.
• Cold, wet weather, lack of sunlight, disease,
  insect damage, and improperly applied chemicals
  are examples.

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Factors that Influence Fertilizer Use

• Chemical and physical condition of the soil
• Crop to be grown
• Climatic Conditions
• Time