Easy⏱ time45 min$ cost4

Soil Erosion Model

Pour 'rain' over bare and planted soil to see how roots hold land in place.

Result first

The build

Step 01

One bare, one planted, one mulched.

Step 02

Set each at the same slope with a catch cup.

Step 03

Pour water equally over each.

Step 04

Measure soil washed out of each.

Working Principle

Plant roots and mulch hold soil together and slow the water, so far less soil washes away than from bare ground.

The science behind it

Vegetation reduces erosion by anchoring soil and absorbing rainfall energy — key to protecting farmland and slopes.

Take it further

Sand, gravel and charcoal layers visibly clear muddy water — a model of natural and plant filtration.

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