To correct improper planting depth and other sub soil issues, the soil must be removed from around the root zone – without damaging the tree’s sensitive roots. For this reason, an arborist will use an Air Spade to remove the soil. Using an air compressor, the Air Spade’s specialized nozzle forces air into the soil at 2x the speed of sound. This supersonic air flow can be utilized to reduce soil compaction, increase aerations, and can be used to incorporate organic matter into existing urban soils without damaging the sensitive root system. The Air Spade allows the arborist to physically remove excessive soil and regrade the area if necessary, so the roots are once again just a few inches from the top of the soil.