An essential tool in organic care is a pneumatic device called the 'Air Spade' that utilizes compressed air to safely and efficiently break up difficult soil...
Accessing root systems with an ‘Air Spade’ is done for a number of reasons. An arborist may want to check for root rot beneath the surface, break up compacted soil that has been preventing nutrient and water flow to the roots, and to diagnose and remediate other root-based issues.
For a long time, the problem of defective root systems was a great source of aggravation to arborists because accessing them was so laborious. The cost of physically digging to expose buried roots was high for tree-care companies and clients alike, and that was just for a diagnosis.
The 'Air Spade' uses compressed air to break up and remove soil. It works much more quickly than conventional digging and it eliminates the danger of damaging tree roots or utility lines.
When the root zone of a tree lives in compacted soil, the rest of the tree is negatively affected. Without the proper flow of nutrients and water moving through the root system, trees become stressed. In turn, that stress opens trees up to insect and disease problems that they would otherwise be able to fight off.
Compaction can be the result of a construction project or simply everyday vehicle or foot traffic over the roots leading to the gradual compaction of pore spaces within the soil structure. This prevents the penetration of root growth and water through the soil, whilst affecting the bioactivity and nutrient recycling process that should take place within the soil.
The process involves a large Air Compressor and an Airspade being used to apply a high-pressure jet of air at 1500mph to the soil. This will loosen any compacted areas of soil, clear the fine roots and not damage any of the live parts of the tree.
Whilst this is being a completed we often add a slow release tree fertiliser and biochar as ameliorants to the soil. Once this process is complete, several ton of woodchip mulch are applied to the area. This will help to prevent further compaction, protect the fine roots from frost damage, help retain water within the soil and aid the nutrient cycle.
You can see this process in the below photos of the Oak Tree on Carlton Playing Field.
Making a start on the soil decompaction at Carlton
Nicki got let out of the office for the day...
The soil decompacted, Biochar and slow release fertiliser added and a layer of woodchip mulch...