Sand or Soil?
Source:
Grampian National Nature Reserves, activity guide (SNH)
OBJECTIVES
- To show differences between sand dune soil and garden soil
- To introduce the idea of organic matter
Time
10 minutes
You will need
- 2 flower pots
- sand and soil
- stop watch
- water
- tray
Did you know?
Tough, specialised plants are needed to colonise sand dunes. Visit the sand dune systems of National Nature Reserves like Tentsmuir Point and Forvie and see how the front line of sand-binding specialised plants gradually gives way to an increasingly variety of other plants. Dune slacks and dune grasslands hold a huge biological richness of plant and insect species.
The activity
- Get the children to fill one pot with sand and the other with garden soil, and place the pots in a tray.
- Let them time how long it takes for the water to run out the pots
- Compare the times and ask why they are different
- Explain that organic matter is bits and pieces of decomposing plants and
animals which turns sand (bits of gritty stone) into soil. It is the organic
matter in soil that feeds the plants. It is also the organic matter that
absorbs the water like a sponge, which can then be slowly released to the plants.
Adding compost to soil is adding organic matter to provide better water
retaining properties and more food.
Suggested Follow up
- Visit a beach with a sand dune system and compare and contrast the change in plants as you walk towards the sea. Look closely at the roots of the dune grasses and touch them where the wind has exposed the roots. The roots are designed to cling onto shifting sand and they feel almost 'sticky' to touch.
- uy a compost bin for school so that children can watch the decomposing process.
Additional Information
Curriculum Links
Science - main
Age Range
1,2,3