7/27/2019 Compost Watch
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500 Harris St Ultimo
PO Box K346 Haymarket NSW 1238
Australia
Tel: 02 6217 0111
http://play.powerhousemuseum.com
This work is licensed under the Creative
Commons Attribution-NonCommercial-
ShareAlike 2.5 License.
THE KITCHEN & GARDEN
Make & Do Activity Kit
Compost watch
In this experiment we observe what happens to organicmatter over time as bacterial organisms do their job to
break it down. We explore the concepts o recycling,
reusing and composting.
Time: 30 minutes +
Difculty:Hints: This is a messy activity and a
good one to do outdoors in the garden.
Take your materials to
a workbench or into the
garden. Adult step: Make
sure your ood scraps and
garden clippings are cut
into small peices.
1.
Rip your waste paper into
small peices and place a
thin layer into the bottom o
the jar. Dampen it slightly.
2.
Place a thin layer o lea
litter or grass clippings on
top and dampen.
3.
Place a layer o ood scraps
on top and dampen. Repeat
steps 2,3 and 4 until your jar
is ull.
4.
Place the lid on to
discourage insects but
don’t screw it down as your
compost needs air. Place
your composter in a sunny
spot.
5.
Watch over the next 2-3
weeks as the ood scraps
break down. Some will
decompose aster than
others. Soon it will be
compose or your garden!
6.
• a large lidded glass
or clear plastic jar/
container
• waste paper (chemical
ree and unprinted)
• ruit and vegetable
scraps
• dry lea litter or grass
clipping
• water (a spray bottle
can be used)
What you will need:
9
7/27/2019 Compost Watch
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Page 2
500 Harris St Ultimo
PO Box K346 Haymarket NSW 1238
Australia
Tel: 02 6217 0111
http://play.powerhousemuseum.com
This work is licensed under the Creative
Commons Attribution-NonCommercial-
ShareAlike 2.5 License.
THE KITCHEN & GARDEN
Make & Do Activity Kit
What’s going on?
Bacteria is doing it’s job
At the beginning o your
composting process microbesstart consuming the materials you have added.
When they do this they produce heat which
encourages the arrival o heat loving bacteria and
other micro-organisms. Some compost piles that
are outside in the garden can reach 40-60 degrees
Celsius!
Bacteria decompose the things in your compost
by releasing chemicals, or enzymes, that break
down your ood scraps, so that they can absorb the
nutrients.
Well balanced and healthy compost
It is good to add lots o nitrogen-rich plant scraps
(called greens) and bits o paper (called browns).
You can also add woodchips and coee grounds
as browns. It is important to balance these two
elements in your compost. I there is too little
nitrogen, the microbes may not be able to raise
the pile’s temperature enough to kill diseases and
dangerous bacteria, or to attract the heat lovingbacteria. However i there is too much nitrogen the
bacteria will produce odorous ammonia gas, and
not be able to survive.
Is your compost smelly?
A lack o oxygen is the likely culprit or bad smells.
Without air, the bacteria produce methane and
other gases that can give o the odour o rotten
eggs!
Compost watch
9
Hair - the slow decomposer
Not everything decomposes at the same rate.
Hair is good in compost, because it contains lots
o nitrogen, but it is very protein rich and can
take a very long time to break down. Most hair
takes about a year to decompose but with the
right conditions it can last or thousands o years.
Decomposition is aected by temperature, the
amount o oxygen, the amount o water and the
presence o microorganisms. Some mummies rom
ancient Egypt still have their hair because they have
been well preserved in air tight, dry caskets.
What else can I do? Make a worm arm or ood composer
By setting up a worm arm or ood composer at your house, at or even at your school, you are helpingto:
1. reduce the amount o rubbish that is dumped intolandfll.
2. make rich soil that can be dug into the garden toertilise plants and grow more o your own ruit andvegetables.
3. reuse and recycle the waste rom your kitchen.