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Soil Erosion Demonstration

Gather 4 or 5 one- or two-liter plastic pop bottles. Fill the bottles with hot water and peel off the labels.

photo of a 1-liter plastic bottle with its label beginning to peel











 


Cut about one-third of the side of one bottle. This will hold the soil. Cut a hole through a second bottle and insert the first bottle through this hole.

photo of a bottle being cut with a utility knife














Using a pair of pliers, carefully heat a needle. Pierce a bottle cap with the needle. This will be used as a cap for the top drip bottle whose bottom has been cut off to form a funnel.

photo of a bottle cap being pierced with a hot needle that is held by pliers














Stack the bottles with the drip funnel at the top. A spacer bottle without a top or bottom is in the middle.

photo of an erosion model using plastic bottles














Place water in the top funnel and observe the clarity of the water as it flows from the soil bottle to an overflow cup.

photo of the erosion model with water dripping through soil to create runoff














Experiment by applying different mulches to the surface or by using soils with different percentages of organic matter (garden versus forested soils).

Soil high in organic matter and soils covered with mulch will yield clearer runoff.

picture of the clear runoff from soil low in organic matter














Bare soils or soils low in organic matter will yield much dirtier runoff.

picture of the very dirty runoff from soil high in organic matter