Erosion experiment.

One of our topics this term has been "Water". We've looked at pollution, floods, drought, rainfall, and important scientists like Dr John Snow, Robert Koch, Louis Pasteur and Joseph Lister.
This was a water experiment to show how trees help to prevent erosion. Erosion is when rain hits the ground really hard and farmland gets destroyed.

First of all, we got two trays, next we poured soil into the trays.

Then we cut some straws up and put them in one of the trays of soil. Then we put some fluff on the top to make it look like the leaves on trees

We got a plastic cup with really big holes in the bottom. We had to tape some of it up on the bottom. When we poured 500ml of water through the cup, it looked like real rain.
First we started on the tray with no straws in. The soil went all squelchy and it had mud slides. It looked like a swamp.

When we poured the water on the fluff, the fluff stopped a bit of the water getting on the soil. A few of the trees collapsed. When we took the fluff off and looked down, it looked a lot drier than the other tray.