1. Plant Fertility

2. Terms and Definitions Essential Nutrient Deficiency
Plant dies without it
Inadequate amounts = plant shows deficiency
Required for yield
Required to complete lifecycle
Deficiency
Plant condition where an essential nutrient is not adequately supplied

3. Terms and Definitions Symptom Fertilizer
A visual sign or condition that results from a deficiency: aids in diagnosing a deficiency.
Fertilizer
Natural, manufactured, or processed materials that contain one or more of the essential nutrients; available in: dry, liquid, and gaseous form

4. Essential Nutrients (18)
Non-mineral – from air and water
Carbon (C)
Hydrogen (H)
Oxygen (O)
Primary Macronutrients
Nitrogen (N)
Phosphorus (P)
Potassium (K)…aka “Potash”

5. Essential Nutrients Secondary Macronutrients Micronutrients
Calcium (Ca)
Magnesium (Mg)
Sulfur (S)
Micronutrients
Iron (Fe) – Zinc (Zn)
Nickel (Ni) – Copper (Cu)
Manganese (Mn) – Boron (B)
Chlorine (Cl) – Cobalt (Co)
Molybdenum (Mo)

6. “The Big 10” 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

8. Plant Nutrient Availability
** Most nutrients cannot be taken up by plants as the “stable” element. Plant nutrients are available as ions:
Cation
Positive-charged ion
Anion
Negative-charged ion

9. Plant Nutrient Availability
Primary nutrient forms:
Nitrogen
Ammonia (NH4+)
Nitrate (NO3-)
Phosphorus—hydrogen phosphates
H2PO3- & HPO32-
Potassium K+

10. Plant Nutrient Availability
Other nutrient forms:
Calcium (Ca2+)
Magnesium (Mg2+)
Sulfur—Sulfate (SO42-)
Iron, Copper, Zinc, Manganese & Nickel
(Xx2+)
Chlorine—Chloride (Cl-)
Boron—Borate (BO33-)
Molybdenum—Molybdenate (MoO42-)

11. Primary Nutrient Functions
Nitrogen Functions
Occurs mainly in protein
Component of chlorophyll (green color)
Promotes vegetative growth
Nitrogen Deficiencies
Mobile nutrient
Deficiencies occur in older leaves first
Chlorosis and stunted growth

12. Primary Nutrient Functions
Phosphorus Functions
Major component of chromosomes (DNA & RNA)
Energy transfer and storage—promotes root development
Promotes maturity—fruit and seed formation
Phosphorus Deficiencies
Stunted growth
Leaves darken and turn reddish purple (grasses) or bluish (legumes)
Discoloration occurs in younger leaves

13. Primary Nutrient Functions
Potassium Functions
Synthesis of protein, carbohydrates and chlorophyll
Regulates nutrient and H2O absorption by plant roots
Promotes seed (grain) development and size
Potassium Deficiencies
Occurs in older leaves
Chlorosis or speckled leaves
Weak stems/lodging

14. Soil pH
What is pH?
Measures the concentration of H+ ions in a substance
Concentrations measured by a factor of 10 (ex: pH of 1 is 10 times stronger than 2, etc.)
Range 0-14
Neutral pH = 7
<7 = acidic
>7 = alkaline or basic
Iowa soil pH: 6 – 7.5

15. Soil pH
pH affects nutrient availability

16. Soil pH
Different crops prefer different pH levels:

17. Changing Soil pH Lowering pH (increasing acidity)
Adding sulfur compounds
Adding nitrogen fertilizer
Good soil drainage
High rainfall
Parent material high in acid elements

18. Changing Soil pH Raising pH (increasing alkalinity)
Adding lime (CaCO3)
Poor drainage
Low rainfall
Parent material high in alkaline base elements