This term we have been looking at different types of soil.
What is soil?
Soil is the loose upper layer of the Earth’s surface where plants grow. Soil consists of a mix of organic material (decayed plants and animals) and broken bits of rocks and minerals.
One week we bought in some soil samples from home. We then worked in groups of 3 to look at our samples closely. This was very interesting because everyone could see something different in each soil type. We had to do the following….
- Look at the soil and describe characteristics such as colours and layers.
- Spread the soil on a piece of paper and look for details such as types of particles and leaves
- Use the magnifying glass to look at particles closely
- Rub the soil between fingers to feel its consistency
The next lesson involved looking at 3 different soil types; sand, silt and clay. Our investigation question was ‘How much water do different soils hold?’
We set up three filter systems using empty plastic bottles, chux cloth and cups. Each filter system was for one soil type. We placed a cup of each soil in each bottle along with a cup of water. We then timed for 10 minutes to see how much water would move through each soil type. After the 10 minutes were up we used measuring cups to measure how many millilitres were in each cup.
We all discovered that clay allowed the least amount of water to pass through into the cup. Most of us found that sand allowed the most amount of water to pass through into the cup, however silt was very close behind with this.
What the results tell us about these soil types….
Next lesson we talked about our results and the reasons why. Sand has the largest sized particles between the three, followed by silt then clay.
People use this knowledge and undertaking of soil to help them with planting certain species of plants in different areas. A good knowledge of soil types is also needed when building houses because you need to make sure the foundation is stable.
We will continue to look more into soil this term to see what else we can learn and discover.