What is a Compost Bin?
7th Grade Science
Alamo Heights Junior School
WHAT IS A COMPOST BIN?
 A compost bin is an amount of waste, (such as organic, rotting
food, dead leaves and small, dead (micro)organisms, and
animal manure) put together, usually for gardens.
 It is similar to fertilizer, but easier to put together.
 The nutrients in the compost helps the soil, and plants in it to
grow big, healthy, and strong.
 Compost bins help save money, and keep your
plants/garden growing healthy and happy. Also, they get
rid of rotting, old food in a person’s home.
HOW A
COMPOST
BIN WORKS
A compost bin is a
container or place
with a pile of organic
scraps that due to
decomposers, breaks
down into the soil
giving nutrients to
plants which
eventually die go into
the pile as well and
start the cycle again.
Leaves
Oxygen
Plants get nutrients from
decomposed organics that then give
plants: humus, carbon dioxide, heat
and water. Then plants die and go to
the compost Bin to restart the cycle.
Food Scraps
Animal Waste
Microorganisms
One example of an
effect of a compost
bin is giving
nutrients back to the
earth from
decomposing plants,
animals, and other
decomposable
materials.
Why a compost bin?
 It helps eliminate trash by decomposing it and
giving nutrients back to the earth.
 Creates fertilizer for the school garden.
 As a class, I propose that we set up a container in
outside for students to place their decomposable
items.
 This would then be taken to the compost pile by the
garden.
Producers, Consumers, and
decomposers
Producers
 Producers are mainly plants and some plankton that
make glucose from the energy of the sun. Primary
consumers eat the producers which helps the food
chain move along.
Consumers
 Most consumers are animals which eat producers
and other consumers depending on what level they
are on in the food chain. Consumers help continue
the food chain.
Decomposers
 Organisms like mushrooms are decomposers.
Decomposers break down dead organisms and
waste which makes the food chain start over again
and repeat the food chain.
What is a Food Chain?
 A food chain is a series of steps in which organisms
transfer energy by eating and being eaten.
Decomposer
Quaternary
producers
Consumer
Tertiary
Primary
Consumer
consumer
Secondary
Consumer