What is Compaction?
Compaction destroys soil structure because it increases the density of the soil by packing the particles closer together; this causes a layer within the soil profile that is impregnable to plant roots, water and air. It can occur in the topsoil and the subsoil layers.
Topsoil is easier to restore than subsoil but the latter cannot be ignored as rooting alone will not break up or restructure a compacted subsoil.
Main causes of compaction
- Misuse of heavy equipment
- Trampling or trafficking over soils
- Handling soils when wet and plastic
- Stockpiling soils inappropriately
Danger signs of compaction
Anaerobism and waterlogging are the biggest soil-related causes of plant failures in landscaping projects but both can be avoided with the right ground preparation.
How you can detect compaction
- Ponding of water on the surface
- Resistance experienced when pushing a soil probe or spade into a soil
- Black, anaerobic layer with a sour odour in a turf-rooting layer
- Uneven plant growth
- Yellowing leaves
- Waterlogging
- Poor root development and shallow root systems
- Anaerobism