Arborist uses an "air spade" to remove soil from a big rootball in about a minute.

[Burl]

I am amazed at how effective this is. Could this, perhaps scaled down, have an application in bonsai? Has any of you used compressed air to remove soil? Would bonsai roots be to delicate?
The action starts around 1:40

 

[Gabler]

I use a water spade.

 

[Bonsai Nut]

I've never seen an air spade. I'm not sure how different it would be than using a pressure washer (with water) or for the matter a hose with a jet nozzle... though with an air spade you don't have as much mess.

Personally, I don't use hoses with air OR water... and do all my rootwork by hand with tools. I have just learned I get much better results - particularly because I can feel the roots and where they run and get a better idea how to untangle them.

 

[Gabler]

I should clarify: I use a water spade (i.e. a garden hose) to remove field soil from collected trees.

 

[Michael P]

In 40 years as a landscape architect, I've never seen an air spade used that way. I think this is because air spades are expensive equipment and not available for most tree plantings. In my practice I always specified that root flares must be exposed and circling roots cut, usually with hand tools. But the air spade does make quick work of it. BTW, air spades blow soil and dust everywhere and are much messier than hand work or water.

Air spades are mostly used for basal excavation around existing trees to diagnose problems, to correct soil compaction, and when trenching is necessary through the root zone to reduce damage to roots.