Soil Erosion

First we cut out the sides of three plastic bottles. Then we glued them on to a piece of wood using a glue gun- leaving the neck of the bottle sticking out over the edge.

 We then 2/3 filled the bottles with dirt. We carefully got some grass (still with its roots) from outside and put it in one bottle. We filled the next one up with twigs and leaves. The third one we left as is.

We strung a cup under each bottle.  Then we carefully poured the same amount of water into each bottle. The one with grass in it drained clear. The one with the leaves and twigs drained more quickly than the first one and was dirty. The water came out of the third one really quickly and left a trail where it had been. The water was really muddy.

This showed us what happens with soil erosion and how plants and trees really help holding the soil together.