FERTILIZERS
AND GRASS CYCLING
THREE MAIN POINTS:
1.
Know why, how much, and what kind of fertilizer
to apply.
2.
Fast release, high nitrogen fertilizers have the
potential to cause plant problems and water
pollution.
3.
Grass cycling is an effective lawn fertilizer, and
saves money and time.
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FERTILIZERS
AND GRASS CYCLING
What’s Inside Your Binder?
-Course Slides
-Fertilizer Worksheet
-Grass Cycling Facts
-Selecting and Applying Fertilizer for Water Quality
Protection
-Fertilizer Basics
- Self Assessment ---HOMEWORK!---Fertilizer Worksheet ---HOMEWORK!---
See the Addendum for:
-Organic Fertilizer Descriptions (pages 37-40)
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Why Do We Fertilize?
Why do we fertilize?
 Replace nutrients that we’ve removed through harvest,
pruning, mowing, etc.
 Aid plants not naturally adapted to some soils
 Push plants to meet the function that we desire
What is the function of landscaping?
 Beauty, visual satisfaction – green leaves, colorful flowers
 Planting for function – turf to play on, visual screen with
hedge
Consider PLANT FUNCTION before we consider
FERTILIZER.
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Your Clients Want
Clean Water
Less Greenwaste
No Pesticides
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Fertilizers
Organic & Synthetic
Reading A Bag of Fertilizer:
What do the three numbers on a fertilizer bag
stand for?
5
Example of
Synthetic
Fertilizer
6
Example of Organic Fertilizer
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N-P-K
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N-P-K
Nitrogen - Phosphorus - Potassium
Nitrogen (N)
Stimulates photosynthesis, used for vegetative growth
Sources:
 Grass clippings and green leaves
 Organic sources
 fish emulsion
 blood, fish, cottonseed, soybean or alfalfa meals
 high nitrogen bird or bat guanos
Synthetic fertilizers
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N-P-K
Nitrogen - Phosphorus - Potassium
Phosphorus (P)
Stimulates flower, fruit and root production. Rose fertilizers have
higher levels of phosphorus.
Sources
 Synthetic fertilizers
 Organic sources
 Rock phosphates, bone meal, high P bird and bat
guanos.
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N-P-K
Nitrogen – Phosphorus - Potassium
Potassium (K)
Stimulates plant vigor and disease and pest resistance
Sources
 Synthetic fertilizers
 Organic sources
 horse manures
 kelp
 mineral
 some soils
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Nutrient Solubility
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Soluble & Insoluble Nutrients
Soluble = fast acting
Insoluble = slow release
How do plants get nutrients in nature?
Slow Release (insoluble) fertilizers closer to
natural system
Fast Acting (soluble) fertilizers for emergency
use
Describe a situation where a plant might need
a fast acting fertilizer?
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Management Problems with
High Solubility Nitrogen
Fertilizers
1. Wasted resources
Once soluble fertilizers get wet, available all at once.
2. Fast acting fertilizers flood roots with only a
few nutrients.
3. High solubility fertilizers = pollution potential
Only 30 - 50% fertilizers may reach plant
4. Fast acting fertilizers cause pest problems
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Nutrient Source
Greenwaste
Advantage
Disadvantage
- Wide range of nutrients
- Low N-P-K value
- Generated on-site: saves
transport fees
- May require shredding or
composting, depending upon use
- No purchase costs
- Slow release of nutrients
- Compatible with existing
soil micro-organism
population
Organic fertilizer
- Wide range of nutrients
- High material costs
- Benefits soil micro-organism
populations
- Low labor costs with
infrequent app needs
Synthetic fertilizer
– Slow release
- Low labor costs with
infrequent application needs
- Narrow range of nutrients
- High material costs
- Potentially destructive to soil
micro-organism populations
Synthetic fertilizer
–Fast release
- Inexpensive material costs
- Narrow range of nutrients
- Immediate plant response
- High labor costs w/ frequent apps.
- Potentially destructive to soil
micro-organism populations
- Benefit only lasts a month
- Potential to make plants more
susceptible to pest problems 15
Ways To Prevent Problems From
Fertilizers
Avoid fast acting, high nitrogen fertilizers
Add organic matter to soil (compost, mulch)
Add organic supplements for plant strength
and pest resistance
Kelp
Worm castings (worm manure)
Compost tea (a liquid fertilizer made by soaking
compost and other materials)
Adequate irrigation
Fertilize only as much as and when necessary
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Grass Cycling
Leave Clippings:
Haul clippings:
More fertile soil
Must add fertilizer
More stable soil life
Starve micro-organisms
Less compaction
Worse compaction
Healthier roots
Stressed roots
Better pest resistance
More pest-prone
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Grass Cycling Facts
Nitrogen from clippings can be recycled in 2 to 3
days
Average lawn = 300-400 lbs of clippings per 1,000
square feet per year
30 lbs of fertilizer with 8-4-6 analysis
NO cost to buy: Save 35-75% of fertilizer costs
SAVE time: 50% less time
BETTER soil: Adds organic matter addition to soil
SAVE your back: 300 – 400 lbs clippings per lawn
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Fertilizer Field Exercise
Distance of
walking stride
Square footage
of two ‘lawns’
Amount of
fertilizer for
each lawn
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Selecting
and
Applying
Fertilizers
for Water
Quality
Protection
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Review
THREE MAIN POINTS:
1. Fertilize to meet plant FUNCTION
2. Benefits of insoluble and organic fertilizers
3. Grass cycling saves money, time, and fertilizes the lawn
What do we mean by plant function?
What does nitrogen do?
What does phosphorus do?
What does potassium do?
Describe the links between fertilizers and pests:
Ways to prevent problems from fertilizers:
What is grass cycling? Why does it help you?
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Homework
Check fertilizer bags you use:
Look for total analysis, total N, soluble N.
Use the chart to determine how much of this fertilizer to
use and how often.
Write down this information and bring to
next class.
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