2. 22
Composting:
“…the most efficient treatment in
producing an environmentally safe
and agronomically advantageous soil
organic amendment at acceptable
operational costs.”
Boulter et al. (2000) World J. Microbiology and Biotechnology
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• organic materials – e.g. lawn clippings,
leaves or other landscape waste, fruit and
vegetable scraps - are degraded by
microorganisms
• added into the soil to improve structure,
fertility, drainage and water holding
capacity
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4. 44
• Many soils have low fertility and/or poor
structure
• To be productive, nitrogen and other
mineral levels must be raised.
• Chemical fertilizers can leach into
groundwater, nitrate pollution.
• Unless plant residues are returned to the
soil, N fertilizers do not improve soil
fertility, quality or health
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5. 5
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57/29/2013 5
Of the waste Americans produce
–More than ½ is disposed of in land fills
–15% is incinerated
–Less than 1/3 is reused, recycled or
composted
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• Raw materials need to be chopped or
shredded so that soil organisms can reach
them.
• Microbes “eat” organic matter, taking in
large compounds and breaking them into
humus and other soil organics.
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• Brown--symbolizes the carbon
portions; such as paper, dried
leaves, and wood (must be
shredded)
• Green--symbolizes the nitrogen
portions; such as grass clippings,
leaves and coffee grounds
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14. 14
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14
Sawdust 100-500:1 Very high carbon!
Paper 150-200:1
Bark 100-130:1
Wheat straw 80:1
Oat straw 74:1
Corn stalks 60:1
Leaves 40-80:1
Fruit wastes 35:1
Horse manure 25:1
Vegetable wastes 12-20:1
Grass clippings 12-25:1
Apple pomace 21:1
Cow manure 20:1
Coffee grounds 20:1
Alfalfa hay 13:1
Poultry manure, fresh 10:1 Very high nitrogen!
Carbon
Nitrogen
ratios
14
N
C
15. • Pile hot
• Tumblers hot
• Bins hot
• Worm cold
• Trench cold
Aerobic
“
“
“
Anaerobic
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16. 1. How much space available?
2. How much biodegradable material is
available?
3. How much compost will be needed?
4. How much labor can you/staff reasonably
perform?
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1--Place a layer of coarse material several
inches thick for drainage on the ground
2--Place a layer of high nitrogen material ~3
inches
3--Place a layer of high carbon material ~6
inches
4--Place a 1 inch layer of garden soil, or
some fertilizer or “compost booster”
5--Water thoroughly.
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• Plant disease organisms may be
present in soil
• These generally live on living plant
tissue
• There’s no living plant tissue in
compost
• Temperatures in compost “cooking”
process kill disease organisms.
22. • Do not take soil from where there
have been diseased plants
• Plants that are diseased or infested
with insects should not be
composted
• Why ask for trouble?
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• Add chopped
materials in a general
ratio of 30 parts
carbon to 1 part
nitrogen
• Moisten thoroughly
• Turn pile to mix
ingredients
• Take temperature
every few days
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• Temperature should rise, then decrease
• Turn again after temperature drops
• Don‟t turn more than every 3 days
• Takes up to 3 months, depending
60
70
80
90
100
110
120
130
140
150
160
early
little
later
starting
to
cookm
ore
cookinggetting
therepeak
activity
coolingtim
e
to
turn
degrees(approx)
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• Pile can be turned regularly
using a garden fork or a
special auger - Or
• Pile can be constructed, mixed
once and left to degrade slowly
- Or
• Pile can be constructed in
layers (lasagna) and left to
degrade very slowly
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29. • This passive approach will compost very
slowly, and can result in odors escaping if
disturbed before completion
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29
30. 307/29/2013
Aerated static pile
In an Aerated static pile air is introduced to the
stacked pile via perforated pipes and blowers.
This method requires no labor to turn compost
but is weather sensitive, and can have unreliable
pathogen reduction due to imperfect mixing.
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• Commercial products are
available
• Bacterial spores
• Increasing microbial population
increases rate of composting
32. Some people add sweet items in order to
provide microbes a sugar supply
These items lower soil pH
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1stbin
Fill with
raw
materials
Allow to
compost
Turn as with
pile
2ndbin
When first is
filled, start
second
Allow to
compost
Turn first bin
also
3rdbin
Either holds
materials or
gets filled
after second
Allow to
compost,
turning first
& second
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3x3x3 3x3x3
3x3x3
36. Use of perforated barrels, drums, or manufactured
containers - simple to use, easy to turn, require
minimal labor, are not weather sensitive, and can be
used in urban and public areas.
The initial investment can be high and handling
volumes low.
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36
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• Have the simplicity of a pile
• Compost is enclosed
• Easy to turn
• MAY BE TOO EASY
– Turning too often prevents the mix from
reaching good composting temperatures
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Similar to pile composting:
• Add chopped materials in a general ratio of 30
to 1 (C/N) ratio
• Moisten thoroughly
• Turn tumbler to mix ingredients
• Take temperature every few days
• Temperature should rise, then decrease
• Turn again after temperatures drop
• Don‟t turn more than every 3 days
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1. Coarse material several inches thick for
drainage
2. High nitrogen material ~3”
3. High carbon material ~6”
4. Garden soil (&/or fertilizer or “compost
booster”) ~1”
5. Water thoroughly
6. Turn as necessary Repeat
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• Red wigglers (Eisinia foetida)
• Hungrier and tolerate higher
temperatures than „nightcrawlers‟
• Degrade materials rapidly
• Worms eat raw materials
• May eat their own weight daily
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• Foodstuff ground in gizzard
• Microorganisms in worms themselves
and in degrading materials also involved
• Little heat generated
• compost = worm castings
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• Starting materials must be moist
• Higher N than other methods
• C/N ratio not important
• Must be protected from heat and cold
• Must not get dry!
• Many, many worms in 1 pound!
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Slower
Anaerobic microbes do
work
Bury starter material
near new garden
Add small amount of
fertilizer
C/N ratio not critical
Will smell bad if opened
before complete
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Preparation –
• for a small system, 5 to 20 minutes/week
• for a landscape, will vary with
– the amount of material composted
– number of people attending to process (turning,
etc.)
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56. From a few weeks to a few months, depending
on:
•Composition and preparation of feedstock
•Turning/turning frequency
•Outdoor temperature
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• Include oxygen in the mixture to support
aerobic organisms that break down the
materials (STIR)
• Don‟t stir too often, or it won‟t get hot
enough to compost.
• Mix materials on a regular basis
• Aeration will cut down odors
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• Dry air
– Always keep lightly moistened
• Hot
– Place in a shady space if possible
– Always have a cover
• Insects
• Odors
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59. 59
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5959
Bugs happen. They benefit compost &
help to expedite process by breaking down
starting material
No pesticides! Can kill bugs and worms
Freeze starting material before putting in
composter to decrease flies and other
insects
If roaches are a big problem, put DE on
top of pile
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Compost should smell like fresh soil
Foul smells may be due to
Anaerobic conditions – stir to add oxygen
Too much green or large green clumps – add some
browns and stir well
Always make the top layer of the
compost brown
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Possible causes:
• Turned too often, heat doesn’t generate
• Not turned often enough, process is very
slow
• Too much carbon, no food for microbes
• Pile too small, microbes can’t get
established
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• Compost is rarely a disease risk
• To reduce these remote risks:
–Wear gloves when handling
–Wash your hands after handling
–Cover any cuts on hands or arms
–Don’t sniff compost deeply, especially if
• your immune system is suppressed (HIV/AIDS,
chemo/radiation, organ transplant anti-rejection
drugs)
• You have asthma, emphysema, etc.
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• has no chunks of
undecomposed matter
• is dark
• does not feel “slick”
• compresses into a ball when
pressed in the hand
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• Incorporate about 1 – 3 inches of compost
into top soil.
• Mix thoroughly.
• Plant as usual
• Or place it on top of soil and allow it to
work its way into the soil.
• Or – make a slurry and apply
– demo
67. •High in nitrogen and other
nutrients
•Soluble nutrients are released
immediately
•Antibiotic and antifungal
properties are released over the
longer course of brewing
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Properties vary with:
1. Starting materials
2. Length of brewing time
3. Level of aeration and stirring
• Insufficient air will cause it to go
anaerobic and smell foul
72. Compost
• Is a terrific source of plant nutrients
• Is a source of many beneficial
microorganisms
• May control plant disease, both as
compost and tea
• Lowers the amount of organic garbage
going to the landfill.
72
75. • If I should die before I wake,
All my bones and sinew take;
Put me in the compost pile,
And decompose me for a while.
• Wind, water, rain will have their way,
Returning me to common clay!
All that I am will feed the trees,
and little fishes in the seas.
• On radishes and corn you munch--
You might be having me for lunch!
And then excrete me with a grin--
Chortling, "There goes Lee again!!"
7/29/2013 75
http://compost.css.cornell.edu/yourself.html