7 chapter 7 fertilizer white

1

FERTILIZERS AND GRASS CYCLING

Three Main Points:2. 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.

2

Why Do We Fertilize?

Q. 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

Q. 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.

3

Best for the Environment

Clean Water

No Greenwaste

No Pesticides

4

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

7

N – P - K

8

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

9

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.

10

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

11

Nutrient Solubility

12

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?

Soluble (fast acting) and insoluble (slow release)

nutrients.

13

1. Wasted resourcesOnce 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

Management Problems with High Solubility Nitrogen

Fertilizers

14

Nutrient Source

Advantage DisadvantageGreenwaste - Wide range of nutrients

- Generated on-site: saves transport fees- No purchase costs- Compatible with existing soil micro-organism population

- Low N-P-K value- May require shredding or composting, depending upon use- Slow release of nutrients

Organic fertilizer - Wide range of nutrients- Benefits soil micro-organism populations- Low labor costs with infrequent app needs

- High material costs

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- Immediate plant response

- Narrow range of nutrients- 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

16

Grass Cycling

What does grass cycling mean?

Leave Clippings:More fertile soil

More stable soil life

Less compaction

Healthier roots

Better pest resistant

Haul clippings: Must add fertilizer

Starve micro-organisms

Worse compaction

Stressed roots

More pest prone

17

Grass Cycling Facts

Nitrogen from clipping can be recycled in 2 to 3 days (radio isotope studies)

Average lawn = 300-400 lbs of clipping per 1,000 square feet per year

30 lbs of fertilizer with 8-4-6 analysis

Advantages of Grass Cycling

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

18

Fertilizer Field Exercise

Distance of walking stride

Square footage of two ‘lawns’

Amount of fertilizer for each lawn

19

Selecting and

Applying Fertilizers for Water

Quality Protection

20

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 does GRASS CYCLING mean? Why does it help you?

21

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.