Principal Binding Agents | Soil Texture | Dispersion | Slaking
The following animation is a simple illustration of two dry aggregates of a sodic soil dispersing when they are hydrated.
The physical and chemical characteristics that control dispersion are complex, and this animation deals with only one aspect of clay dispersion. The animation aims to demonstrate the difference between exchangeable cations such as sodium (Na+) and calcium (Ca2+) on clay dispersion, and does not detail the effect the concentration of soluble salts in the soil solution may have on dispersion.
Also, in a 'real' soil the composition of exchangeable cations is a mixture of Na+, Ca2+, magnesium (Mg2+), aluminium (Al3+), to identify a few. For simplicity, we have shown the clay particles in the animation to be saturated by only Na+ or Ca2+.