Then we designed an investigation to find out which soil is the most permeable. This means which soil lets the most water through. We found out that the clay soil let the least amount of water through in 30 seconds, and the compost let the most water through.
Then we took a sample of each soil, mixed them with water and left them to settle overnight. As you can see, they all look very different! The clay soil (on the left) had very little organic matter in it and the compost turned the water orange!