Download Fun Earthworm Facts

Fun Earthworm Facts
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These slimy little critters are underground farmers who turn over
the soil like a plough
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In just one acre there can be a million or more of them, eating 10
tons of leaves, stems, and dead roots a year and turning over 40 tons
of soil in the process
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There are 4,400 different species of worms
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There are 2,700 different kinds of earthworms
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The tunnels created by the worms help plant growth by aerating
the soil allowing for better water penetration
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The earthworm lives on average one year
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Worms fertilize the soil with their castings, or simply worm poop,
which contain the recycled nutrients from the debris they eat
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Many earthworms are not native to the United States, most were
introduced from Europe
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Sunlight will kill earthworms
How Do Earthworms Help
the Soil?
Earthworms dramatically alter soil structure, water movement, nutrient dynamics, and
plant growth. Their presence is usually an indicator of a healthy soil system. Earthworms
perform several beneficial functions:
Stimulate Microbial Activity— Although earthworms derive their nutrition from
microorganisms, many more microorganisms are present in their feces, or casts, than in the
organic matter they consume. Increased activity facilitates the cycling of nutrients from
organic matter, and converts them into forms readily taken up by plants.
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Mix and Aggregate Soil— As they consume organic matter, earthworms excrete waste
in the form of casts, a type of soil aggregate. A large portion of the soil passes through the
guts of earthworms, which stimulates mixing of the soil layers. Earthworms can turn over
the top six inches of soil in ten to twenty years!
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Increase Infiltration— Earthworms increase porosity as they tunnel through the soil.
Some species make permanent burrows, which act as major conduits for soil drainage,
particularly under heavy rainfall. High infiltration rates help prevent pollution by
minimizing runoff, erosion, and chemical transport to surface waters.
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Improve Water-holding Capacity— By fragmenting organic matter, and increasing
soil porosity and aggregation, earthworms can greatly increase the water-holding capacity
of the soil.
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Provide Channels for Root Growth— The channels made by deep-burrowing
earthworms are lined with readily available nutrients, and make it easier for roots to
penetrate deep into the soil.
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Bury and Shred Plant Residue— Earthworms are the main agent for incorporating
crop residue into the soil by pulling some into the their burrows and by slowly burying the
remainder under casts laid at the soil surface. This mixing increases organic matter and, in
turn, soil structure and quality.
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How Does an Earthworm
Eat?
Earthworms have mouths...they can even open them wide enough to fit
leaves and other good things. However, they don’t have any teeth!
Follow along to see what happens to an earthworm’s lunch.
Mouth: The mouth opens wide to expose the pharynx.
Pharynx: The earthworm pushes the pharynx, or throat, out of its mouth to grab leaves
and pull them back into its mouth. The food will remain in the earthworms mouth until it
is completely saturated with saliva.
Esophagus: Once the food is sufficiently soaked, it passes from the pharynx, through the
esophagus, and on to the crop.
Crop: The crop is the storage compartment for food and anything else that may be
swallowed. From the crop, the earthworms lunch moves on to its gizzard.
Gizzard: The gizzard is where it all the work is done. The strong muscles, and any stones
that may have been swallowed along the way, work together to grind up the food;
working much like our teeth.
Intestine: Once all the food is ground up, it passes on to the intestine where digestive
juices break it down even further.
Bloodstream: Now that the food is all digested, some of it will pass to the bloodstream,
where it can provide nutrients and energy to the earthworm.
Anus: Anything that is not passed to the bloodstream will be expelled through the anus as
castings...or worm poop, which is very beneficial to the soil.