| Experiment 1: separating the parts of soil. | - Put a sample of soil in a bottle full of water
- close it
- shake it well and let it settle. Sand settles first
- within about a minute
- then silt after several hours
- then clay
- which takes days to settle. Organic matter floats on the surface
| samplebottlefullwater |
| Experiment 2: formation of minerals by evaporation. | Dissolve some table salt in a cup of warm water and leave it in an open place until the water evaporates. Cube-shaped salt crystals appear on the sides and bottom of the cup. This is an example of a mineral forming by evaporation | Dissolvesometablesalt |
| Application in farming | - when desert land is reclaimed
- organic fertiliser is added to the sand
- because it improves water retention and increases the fertility of the soil
| desertlandreclaimedorganic |