Grade 3 · Science · Unit 8 of 10
Caring for Soil
Compost, erosion and healthy soil
What your child practises
Composting, how fertilizer and road salt affect soil, how erosion happens and how plants, windbreaks and cover crops protect soil.
Ontario Curriculum expectation: E1.1, E1.2, E2.2, E2.4–E2.6 · things added to soil, erosion, composting, and ways to keep soil healthy in Ontario
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
Why can too much plastic in soil be a problem?
🧴- it feeds the earthworms
- it makes the soil sweeter
- it turns into compost
- it does not break down and can harm soil life
Show answer
it does not break down and can harm soil life
Hint: Plastic stays in the soil for a very long time.
Question 2
Erosion is when…
🌧️- soil turns to glass
- wind or water moves soil to a new place
- worms eat soil
- soil becomes sand
Show answer
wind or water moves soil to a new place
Hint: Bare ground can be washed or blown away.
Question 3
Mulch is a layer of leaves or wood chips spread on a garden. How does it help?
🍂- keeps moisture in and protects the soil
- blocks all the air
- makes the soil dry out
- kills all the worms
Show answer
keeps moisture in and protects the soil
Hint: Mulch covers the soil like a blanket.
Question 4
Put the steps of soil erosion in order.
- 🟫soil is carried away
- ⛰️water runs downhill
- 🌧️heavy rain falls on bare soil
- 🏞️muddy water flows into a stream
Show answer
heavy rain falls on bare soil → water runs downhill → soil is carried away → muddy water flows into a stream
Hint: Rain falls on bare soil, flows downhill and carries soil to a stream.
Question 5
Who does most of the work in a compost bin?
🪱- the wind
- magnets
- worms, bugs, fungi and bacteria
- the Moon
Show answer
worms, bugs, fungi and bacteria
Hint: These tiny living things break food scraps down.
Question 6
Can it go in a compost bin? Tap an item, then tap its basket.
Sort into: ♻️ compost it · 🚫 not for compost
- ☕coffee grounds
- 🍂dry leaves
- 🥫metal can
- 🫙glass jar
- 🍎apple core
- 🥤foam cup
Show answer
♻️ compost it: coffee grounds, dry leaves, apple core · 🚫 not for compost: metal can, glass jar, foam cup
Hint: Fruit and vegetable scraps, leaves, eggshells and coffee grounds break down. Plastic, glass and metal do not.