Transcript WHERE DO YOU GET YOUR SENSE OF HUMUS?

WHERE DO YOU
GET YOUR SENSE OF
HUMUS?
“Humus: the relatively stable
end product of composting, rich
in nutrients and organic matter
and highly beneficial to both the
soil and plants.”
The Rodale Book of Composting
A compost “heap” may sound
like a disorganized mess,
however, the raw organic materials
provide for a diverse and intricate community of
micro- and macro organisms.
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Microorganisms= Chemical Decomposers
Macro Organisms= Physical Decomposers
Nearly all are beneficial and
each has a role in the decomposition
The Microorganisms:
Bacteria (the work horse of the pile)
Actinomycetes (what gives humus it’s earthy smell)
Protozoa (small role)
Fungi (enter final stages of decomposing)
The Macro Organisms
• Mites, Millipedes, Centipedes
• Sow bugs, Snails, Slugs, Spiders, Springtails
• Beetles, Ants, Flies,
• Nematodes, Flatforms, Rotifers
• Earthworms (Hero!)
All organisms form a complex food chain,
and are categorized as
• first level consumers,
• second level consumers, and/or
• third level consumers
Each level of the food chain keeps the previous level
in check, keeping balance in the pile.
The life purpose of bugs
in a compost pile is to:
Bite, grind, suck, chew, move, displace,
spindle, disfigure, abrade, crush, pulverize,
crunch, crumble and reduce.
The smaller size particles make the organic material
more suitable for the chemical work of the microorganisms.
And of course, they poop.
Food Web of the Compost Pile
Where we get our sense of humus
COMPOST
(organic residues)
Chemical
Bacteria
Fungi (molds)
Actinomycetes
Decomposers
(microscopic)
First level
Physical/
Chemical
Decomposers:
First Level
Beetles Mites Earthworms Millipedes Snails/Slugs Sow bug Fly Roundworms
Rotifera Roundworms Nematodes Protozoa
Second Level
Chemical
Decomposers
Springtails Mold Mites Feather-winged Beetles Beetle Mites
Soil Flatworms
Second and
Third Level
Decomposers
Ground Beetles Psuedoscorpion Centipedes Rove Beetles
Spiders
Predatory Mites
Ants
All first level chemical decomposers feed on the organic matter in the compost pile. The physical
decomposers feed on the organic matter and lower level chemical decomposers.
The higher levels of the food chain feed on lower, according to color.
Adapted from Dindol, D.L. 1971 “Ecology of Compost”
Macro organisms function best at medium
or mesophilic temperatures,
so they may not be present
in the pile at all times.
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Mites: Reproduce quickly; attack plant matter, and eat fungi, but can also be 2nd level
consumer.
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Beetles: Feather winged beetle (2nd level consumer- eats fungal spores). Rove and ground
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Sow Bugs:
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Snails/Slugs: Eats living plant material (keep out of garden) but also
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Ants: First level consumers, pile may be too dry. Ants thought to be beneficial because
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Spiders:
beetles eat dying vegetation; third level consumer.
Eats decaying vegetation: first level consumer.
plant debris. Okay in compost.
fresh garbage and
they bring fungi and other organisms to nests, while bringing back phosphorous and
potassium from deeper levels of soil, constantly moving minerals from one place to another.
Related to mites. They eat insects, small invertebrates, and can control garden
pests. Third level consumer.
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Grubs/Green Fruit Beetle: Grubs are larval stage of adult green fruit beetle. Grubs eat
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Soldier Fly: They feed on anything organic. Larval phase in compost is maggots (although maggots
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Springtails: They feed on decomposing plants, pollen and fungi.Second level consumers.
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Millipedes: They eat plant material; first level consumers.
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Centipedes: Feed on living animals like insects and spiders. Third level consumers.
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Earthworms: Champion Decomposers!
decaying organic matter, while adults eat overripe, rotting fruit. They are C-shaped, white with dark gray at
the tail. Unfolded, they walk on their back, with legs in the air, tunneling into compost. This style of moving
is specific to this species, not the more destructive kinds of grubs.
don’t survive the thermophilic stage). Flies provide ideal transportation of bacteria on their way to the pile,
and are voracious consumers of nitrogen-dominant decaying material. If you are bothered by them, place 2
inches of browns to cover food scraps.
They are both physical and chemical decomposers,
as their castings add bacteria, organic material, available nitrogen, calcium, magnesium, phosphorus, and
potassium. First level consumers.
www.whatsthatbug.com
Fun facts
for Compost Lovers,
bugs and all.
• How many legs
does a millipede
have?
• No, not one thousand…
Common species have
between 36-400,
although a rare species
has 750.
• What is a
detritivore?
• An organism that obtains its
nutrients by consuming detrius
(decomposing organic matter).
• Slugs
have been described as so
undifferentiated in appearance
that one species is frequently
mistaken for
what?
• Half a potato
• What is a
furcula?
• It is the jumping mechanism
of the springtail.
Located on its
fourth abdominal segment,
the springtail releases
the furcula
and is propelled through the air,
up to a distance of
20x its body length.
• Charles Darwin
suggested that
“all fertile areas of the planet have
at least once
passed through the bodies of
what decomposer?”
• The earthworm!
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Compiled by Susan Wingate, Master Composter 2009
©susan wingate photography,
except potato and millipede image