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Grow It 3-5 / Week 09 / Grow It Day
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Week 09 · Soil and Decomposers

Grow It Day

Grow It Day: Compost Bottle
// What soil is made of, and who recycles it
⏱ about 15 min

Grow It Day: Compost Bottle

The family spreads newspaper on the table. A grown-up holds a clear plastic bottle.

Rocket lines up dry leaves, apple peels and a scoop of soil. "Browns and greens!" he says.

Raven hands out gloves. "What do you notice we still need?"

Nova hovers above the bottle. "Remember the four ingredients," she says. "Decomposers need two you cannot see."

  1. Soil is mineral bits, organic matter, water and air.
  2. Sand bits are largest. Clay bits are smallest.
  3. Decomposers like fungi, bacteria and earthworms break down dead things.
  4. Compost needs browns, greens, water and air.
  5. Matter cycles from dead things back into the soil and into new plants.
◇ BUILD A COMPOST BOTTLE
A grown-up cuts the top off a clear plastic bottle.
A grown-up pokes a few small air holes in the sides.
Put in a layer of soil.
Add a layer of browns: torn dry leaves or shredded plain paper.
Add a layer of greens: small pieces of fruit or vegetable peels.
Repeat the layers. Use more browns than greens.
Sprinkle water until it feels like a wrung-out sponge.
Set the top back on loosely. Check it every few days.
Safety first
A grown-up does all cutting and poking. Bottle edges can be sharp.
Wear gloves for soil and scraps. Wash your hands after.
Do not add worms from outside. Let the decomposers already in the soil do the work.
Nothing in the bottle is for eating.
For a grown-up
Ask: which layers do you think will change first? Why?
Ask: what will we do if it smells sour?
COMPOST BOTTLE CHECK
  • Read the question.
  • Tap your answer.
Why does the bottle need small air holes?
The bottle looks dusty and dry. What should you do?
Your bottle smells sour and is too wet. What should you add? Type one word.
WHY THIS EXERCISEMore browns balance a soggy pile.

Fantastic building! Keep checking your compost bottle. Next week we explore the garden food web.

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