FERTILIZERS
“Satisfying the plant’s need for essential nutrients”
ESSENTIAL ELEMENTS
Environmental
Primary Macronutrients
Secondary Macronutrients
Micronutrients
ENVIRONMENTAL ELEMENTS
Carbon (C)
Hydrogen (H)
Oxygen (O)
PRIMARY MACRONUTRIENTS
Nitrogen (N)
Phosphorus (P)
Potassium (K)
SECONDARY MACRONUTRIENTS
Calcium (Ca)
Magnesium (Mg)
Sulphur (S)
MICRONUTRIENTS
Boron (B) Manganese (Mn)
Cadmium (Cd) Molybdenum (Mo)
Chlorine (Cl) Nickel (Ni)
Copper (Cu) Sodium (Na)
Iron (Fe) Zinc (Zn)
Lead (Pb) Cobalt (Co)*
* Sometimes required
FERTILIZER ANALYSIS
All fertilizers are labeled with three
numbers giving the percentage by weight of
Nitrogen (N), Phosphate (P O ), and
5
Potash (K )
2
To simplify the analysis they are
represented by Nitrogen (N),
Phosphorous (P), and Potassium (K)
N - P - K
WEIGHT RATIO ANALYSYS
N - P - K
10 - 10 - 10
What this means is that per one hundred
pounds of product there are ten pounds each
of Nitrogen, Phosphorus, and Potassium
(N-P-K).
All other ingredients are considered and
called filler.
COMPLETE VERSUS
INCOMPLETE FERTILIZERS
A complete fertilizer will contain all elements
N-P-K
An incomplete fertilizer will contain only one or
two of the elements
SPECIAL PURPOSE FERTILIZERS
Azalea/Rhododendron
Camellia
Rose
Tomato
Fertilizer combined with herbicide
COMPARISON OF FERTILIZERS
Synthetic
• Conventional
• Slow release
Natural
• Humic materials
• Manures
• Sewage sludge
CONVENTIONAL FERTILIZERS
Advantages Disadvantages
Fast acting Greater burn potential
Some are acid forming Solidifies when wet
Low cost Nitrogen leaches
Easy to control
readily
Soluble salts
SLOW-RELEASE FERTILIZERS
Advantages Disadvantages
Fewer applications High cost
Low burn potential Limited availability
Release rate varies Release rate factors
Slow release rate
NATURAL FERTILZERS
Carbonous material
• Cottonseed meal (7-3-2)
• Dried blood (12-3-0)
• Bone meal (3-22-0)
• Fish emulsion (5-1-0)
Manures and sewage sludge
Non-carbonous material
Natural Fertilizers-Carbonous
Advantages Disadvantages
Low burn potential Slow response
Slow release Bulky
Contains Expensive
micronutrients Weed seed
Conditions the soil Cold weather
Apply at high rates
MANURES OR SEWAGE SLUDGE
Advantages Disadvantages
Low burn potential Salt problems
Relatively slow Difficult to control
release odor
Contains Expensive per nutrient
micronutrients Weed seeds
Heavy metals
GREEN MANURE
Legumes Non-legumes:
• Alfalfa • Annual ryegrass
• Ladino clover • Crimson clover
• Sweet clover • Oats
• Red Clover • Horse bean
• Soybeans • Rough pea
• White clover
FERTILIZER FORMULATION
Solid
Granular
Powder
Liquid
FERTILIZER APPLICATION
Application techniques
Computing amount to apply
FERTILIZER APPLICATION
Hot weather application
• Nitrogen
• Moisture
Soluble salts
• Garden
• Container
FERTILIZER APPLICATION
Soil type dictates frequency
Plantings and type of fertilizer
Watering or rainfall
Timing
APPLICATION METHODS
Broadcasting
Banding
Starter solution
Side-dressing
Foliar feeding
COMPUTING FERTILIZER APPLICATION
“The Formula”
Application rate Area
(pounds per 1000SF) X (Square feet)
Element content 1000
as a decimal
= Fertilizer product to apply in pounds
COMPUTING FERTILIZER APPLICATION
“The Simplified Formula”
100 = Factor
Element weight
The factor times the square feet, expressed
as a single digit, will provide the quantity
of product per 1000 square feet to apply
PRACTICAL EXERCISE
Garden: 25 x 25
Fertilizer: 5-10-10
Rate: 1 pound per 1000 square feet
PRACTICAL EXERCISE
Lawn: 100 x 40 (Centipedegrass)
Fertilizer: 10-10-10
Rate: .5 pounds per 1000 square
feet
SUMMARY
Essential elements
Fertilizer analysis
Complete versus incomplete
Special purpose fertilizers
Natural and synthetic
Fertilizer formulation
Fertilizer application