Transcript Plant Nutition

Review
 Physical properties of soils??
Review
 Physical properties of soils??
 Soil texture
 Soil structure
 Density
Review
 Chemical properties of soils??
Review
 Chemical properties of soils??
 pH
 CEC
Review
 Chemical properties of soils??
 pH
 CEC
 What is the pH of agricultural soils?
Review
 Chemical properties of soils??
 pH
 CEC
 What is the pH of agricultural soils?
 between 6 and 7
Review
 Chemical properties of soils??
 pH
 CEC
 What is the pH of agricultural soils?
 between 6 and 7
 Why is this range the optimum
condition?
Plant Nutition
Introduction
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How many elements do we find in plants?
Do plants need all the elements in the same
amount?
How does agriculture effect the soil nutrients?
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What is the solution?
Introduction
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60 or more elements are found in plants.
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17 essential
Introduction
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60 or more elements are found in plants.
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17 essential
Macronutrients
Micronutrients
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Enzyme cofactors
Macronutrients
Introduction
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60 or more elements are found in plants.
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17 essential
Macronutrients
Micronutrients
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Enzyme cofactors
Micronutrients
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60 or more elements are found in plants.
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Macronutrients
Micronutrients
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17 essential
Enzyme cofactors
What is the relationship between plant
nutrition deficiency and humans or animals?
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China example
Nitrogen
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Nitrogen role in plants
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Protein
Base pairs for RNA/DNA
Chlorophyll
Hormones (ABA, cytokinins)
Nitrogen
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Nitrogen role in plants
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Protein
Base pairs for RNA/DNA
Chlorophyll
Hormones (ABA, cytokinins)
Nitrogen
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Nitrogen role in plants
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Protein
Base pairs for RNA/DNA
Chlorophyll
Hormones (ABA, cytokinins)
2% of DW
Which type of transport
requires ATP?
Nitrogen deficiency
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Poor, stunted growth
with pale leaves and
weak stems.
Leaves often turn
orange or red, may fall
prematurely.
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Fruit trees
Vegetables
Phosphorus
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ATP/ADP
DNA/RNA
Phospholipids
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Membrane
Phosphoproteins
10% of N
Phosphorus Deficiency
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Poor growth
Fruits are small and
acid tasting
Leaves become
brown or red if P is
severely deficient.
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Corn and grassy
plants
Oldest leaves are
affected first
Potassium
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Cofactor in osmosis
Stomata control
Protein synthesis
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Deficiencies:
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Dull and spare flowers
Low fruit yield and poor
quality.
Tissues become soft
and susceptible to
attack from pests.
Brown scorching and
curling of leaf tips, and
yellowing of leaf veins.
Purple spots may also
appear on the leaf
undersides.
Iron
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Enzyme activator
Required for
chlorophyll
synthesis
When soils are
alkaline, iron may
become
unavailable.
Applications of an
acid nutrient
formula can help.
Zinc
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Energy production
Protein synthesis
Formation of
chlorophyll
Growth regulation
Deficiency Symptoms:
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Delayed maturity
Symptoms occur
mainly in new growth
Short internodes
Decrease in leaf size
Soil, Water and Minerals
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Silicates (SiO4-4)93% of earths crust
Rings of water form around soil particles.
Soil solution
• Cations and Anions dissolve in water.
• 50% of soil vol.
Soil, Water and Minerals
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What are some factors in ion binding to
soil particles?
• Charge ( + & - )
• Size
• Concentration
Soil, Water and Minerals
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Ca2+ vs. Na+
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High conc. of Na+ vs. Low conc. of Ca2+
Soil, Water and Minerals
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Why is it important to know these rules?
• Salty soils – high levels of Na+
• Useful ions end up in ground water
• Southwestern US
Acidic Soils
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Acidic soils are nutrient poor.
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Where do we find acidic soils?
Why?
Acidic Soils
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Acidic soils are nutrient poor.
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Where do we find acidic soils?
Why?
CO2 + H2O ↔ H2CO3 ↔ H+ + HCO3H+ displaces other cations.
Acidic soils bring toxic ions into the soil
solution
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Aluminum ions
Cation Exchange
• CO2 released from
roots (indirect H+)
• H+ can also be
secreted (direct)
• H+ then replaces the
mineral cations in soil
• Minerals are released
• Roots uptake the
minerals
Nitrogen
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Why is Nitrogen important for plants?
Nitrogen
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Why is Nitrogen important for plants?
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Proteins, DNA, RNA, chlorophyll, and
hormones
Nitrogen
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Why is Nitrogen important for plants?
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Proteins, DNA, RNA, chlorophyll, and
hormones
Do you remember the symptoms of
nitrogen deficiency?
Nitrogen
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Why is Nitrogen important for plants?
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Proteins, DNA, RNA, chlorophyll, and
hormones
Do you remember the symptoms of
nitrogen deficiency?
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Poor growth
Weak stems
Discoloration of leaves
Nitrogen and Bacteria
• N2 can not be used
directly by plants
• NO3- or NH4+
• Nitrogen fixation
– Soil bacterial Rhizobium
– The conversion of N2
into NO3- or NH4+
• Legumes are rotated
with other crops to
enrich the soil.
Nitrogen Fixation by Bacteria
Review
• Macro and Micronutrients
– Importance to plants
– Deficiency symptoms
• Ion and soil particle interactions
• Cation exchange
• Nitrogen fixation