Air-spade

Lee Winger

Are any of you Aussies using the Air-spade or soil-pick, for vertical mulching, radial trenching, and root collar investigation?

I've been trying to sell these services over here, not easy..........

Urban Treecare NZ

Hey Roller,
Im in Nz but we have used the air spade with good success on a few projects here, mainly for soil contamination and root exploration around building sites and developments as part of a plan or resource consent process. Certainly have their place but have to get in with the right kind of people.

redstree

Here in the states there are a few air spades around but not that many.

They have their place in spite of their expense. Only part of the cost is the tool. The far larger cost is the compressor. You really have to have this thing working all of the time to make it worth while. Sometimes people will calculate the cost into one large job and then rent a compressor for additional smaller job as needed.

Great tool for root collar investigations, compacted soil remediation, and vertical mulching.

Just be sure to wear hearing protection. Buy the best you can get. Look for protection with a 30dB rating. Over the ear being preferable to ear plugs.

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Drive a MINI, the most fun you can have with your trousers on.

kailas

Interesing,
this week I have to work with airspade, we rent a 4500lt compressor that we'll move in three different places, so we concentrate the work in three days, to share better the cost of hiring.
An old and fantastic beech pendula to decompact and oxygenate the root system, maybe we'll add also some mycorizze to reactivate the soil, then
a cedar deodara that had a lightning struck last winter, I gave mycorizze to the soil, and I treat the big wound with a special formula: mix of clay, propolis, equisetum and bario salt, it's like an experimental treatment.. they use it in organic farming with fruit trees. in addiction using airspade we will help the tree with new oxygen on the soil for more energy and health.

Others are some oak very depressed after an ice storm some years ago, locate on top of little hill with rock under few ground, around these there is grass and turf..moss, here I don't know how it will work the airspade, maybe I have to remove the grass\ground slice(?) and replace it after.. or maybe also possible other ways of doing it... like making only some rays around the tree..
Why to use vertical mulching, i mean.. what is it for?

Sean Freeman

Roller, as others have said air-knives are used here just not very often (not often enough IMO). There's a few more serious companies that have their own and do root crown inspections, decompaction etc.... But no not a huge market.....(its in the soil mate many Arborists have a little difficulty getting their heads around the soil-root environment).

Eric Frei

Funny isn't it Sean.

Frankly the cost of getting one is nothing compared to trucks, chippers, stumpgrinders. In fact they're only just dearer than a big chainsaw.

The difference is you get work for those other bits of gear.

No-one really hires them out, you have to find a company that has one and get them in. If an arb shop hired them out minus a compressor of course there'd perhaps be more call for it.

I'm watching a large council euc die slowly. Now it's foliage is about 50% what it was 2 years ago but no dead wood yet. It's declining alright. You know how you should have taken those pics 2 years ago but didn't etc.

Anyway, that tree if it were decompacted - aerated, drenched with a tea and mulched would be fine. So would so many others.

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Sean Freeman

I agree entirely its a real shame that more Arb businesses when they do have disposable capital (yes I know when would that be???) don't see the sense in investing in such tools.
If we left it to the "market place" (in Oz at least, since this is where I live and work) there would be no call for modern Arboriculture at all.....just top and lop mate she'll green up and if it don't well then just plant another.........

If we truely believe we have an understanding of tree biology that is not common knowledge, that we can offer positive long term solutions to a great many tree related concerns then that is what we should be presenting to the great unwashed.

We are not all working in the same areas I know that some of us focus on the coal face..saw in hand, 30-40m up a declining leaning Euc...I really understand that, I do....you know from time to time (increasingly rarely) I'm up there myself!
However working in the area of plant health care does affect the way you percieve the problems and the potential solutions...the air knife can be an important tool in that particular field of Arboriculture...and yes I wish they were available to hire!

TreeSpecialist

I've had an air spade for almost 12 years and found that it paid for itself in less than 30 days of use.

Root collar exams by hand would take two men 6 to 8 hours - with an air spade, 1 man 15 to 30 minutes - 2 hours for really tough ones.

We rented a compressor (185 cfm) at first for about $45.00 per day. We bought a used compressor after about a year of renting one and found that we use the air spade even more often now that we own a compressor. (Used compressors work fine and are considerably cheaper than new. )

Going behind our competitors we find that they stop as soon as they find and remove a single girdling root (GR). They leave behind another dozen or more GR's that continue on down the root collar or out the root flares.

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Eric Frei

Do you cut them GR off? What about decay so close to the trunk?

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TreeSpecialist

Yes, girdling roots need to be cut off the tree.

To leave them is to strangle the tree resulting in a slow death.

The number of girdling roots, the species of tree, whether or not they have grafted into one another or worse grafted in the main flares, presents problematic questions to the arborist who has only experience and his gut feeling on what to cut and what to leave.

We always follow up with a deep root, high-pressure fertilization tailored to stimulate new root growth and recommend repeated visits and/or additional fertilization treatments.

Recovery varies with species. Live oaks (Quercus fusiformis) recover slowly. Magnolias (Magnolia grandiflora - famous for girdling roots around here) have shown positive response in as little as 2 weeks!

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kailas

What you will use vertical mulching trenches for, compared to a normal all round the tree treatment?

Eric Frei

The concept is to improve air penetration and drainage. Often the holes either air blasted or drilled/cored are filled with coarse sand, fine gravel woodchip etc.

Here we have some serious compacted clay, it would help, a lot.

Some will put fertilizer down them holes too but I'm a little skeptical of that. It could turn nasty.

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TreeSpecialist

Vertical mulching at our company usually involves backfilling the holes with compost. It keeps the holes open enough to allow for air and water to penetrate while gently "feeding" the soil.

We used to use a drill with a 2" auger bit, but with the air spade, it's faster and easier. Holes are usually spaced from 12 to 18 inches in a grid starting about 1 foot from the tree and continuing out to several feet beyond the drip line.

We've also tried Dr. Watson's method of radial trenching - trenches 10 to 12 inches wide, 8 to 10 inches deep radiating out from the trunk at 45º angles.

One client even let us air spade her entire front lawn. We turned over about 2 thousand square feet of soil down to a depth of 12 inches and added about 20 yards of compost to the root zone of a large American elm. While it didn't give me the miracle results I was hoping for, the tree is significantly improved and the client is happy.

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Eric Frei

What sort of compost are you putting down there?

How deep are the holes?

Any toxicity issues?

Sometimes decomposing organic matter can give of poisonous gases like methane and amonia. My concern is if the compost is too raw and the holes become a waterlogged then you could end up with toxicity issues. But depends on the soil too. Any experience with anything like that?

I know I killed a bunch of Azalea shrubs once when I threw a handful of organic lifter under each before backfilling.

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TreeSpecialist

Not all composts are alike. Many are simply rotten mulch.

We use a "finished compost" - one that has cooled down and been professional produced by the organic folks here in Central Texas.

We've never had a problem with burning.

Holes are drilled down about 18 inches. Below that, you cant' find many roots in the heavy clays we sometimes drill into.

And in many sites around town, we can't drill down more than a few inches because of rock. In those areas, we drill until we hit rock.

By using a nicely finished compost and by putting in 4 to 10 times as many holes as my competitors, I get results they don't. When irrigated, the trees get a "compost tea."

Check out Soil Foodweb, Inc. for more information about composts.

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Lee Winger

i'm using compsted wood chip and grit/pea shingle, i'm using an organic product in my deep root fert rig, and a few other organic bits and bobs, chelated iron and micro nutrients..

damn hard service to sell, but we've seen some great results, and customers are happy..

TreeSpecialist

If you start taking some before and after pictures of your work, it makes it easier to sell.

Everyone wants an instant fix these days.

Organic approaches take longer but in the end work far better than chemical applications.

The "before and after" pictures may be over several months to several years.

Arborists have to be salesmen first and arborists second. If you don't sell the job, you never get the chance to show your client what you can do.

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kailas

Today air-spade work to a big oak in the center of Milano,
we dig 2 meter around the tree only cause the tree is now confined in a round and upper spot, 5 yr ago they dig for car parking underground and remove all the roots they could find, yr after yr the oak has dried the tops.
Pakisandra was under the tree and it turned yellow too. We remove pakisandra and exposed the roots.
Found some broken roots underground, a couple was very huge but cut in a bad way (looks like excavator's bite) 1 mt or little more from the tree.
there was evident sign of rottten roots. Was difficult to dig with the spade here cause of many pakisandra roots evrywhere, the air was not passing under so we decide to remove manually the white pakisandra roots, trying to not damage the tree root system.
After a bit more decompacting the soil. we pour on the exposed roots a solution of healthy fungy mix with water, and filled evrything with lavic gravel with few activeted ground.
Hope is gonna help for the tree, Iìll wait to sse him very green and healthy this summer!

Eric Frei

That sounded like a great job, you need to show us some pictures.

I'd like to do stuff like that more so these days than just cut trees.

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kailas

Yeah, was nice job, very few like this, but make you feel really "tree doctor", i mean you really feel you're healing the tree, ....or at least trying to do so...
cause most of the time just have to trim and cut like a machine!!
Few pics we made, when they come to me I will sure post them here.
Ciao guys, it's time to go work..

kailas

Here are some pics..













hope you enjoy it

ciao
max

Drouin Tree Service

Good work Rolla!

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Drouin Tree Services | Excavator Hire - Drouin and SE Gippsland | Landclearing Melbourne

Eric Frei

Kailas, thanks for the pics, very good!

How do you think that oak is for stability?

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kailas

Ohhh...
on the house side roots were not damaged,
but on the other side... very bad, i guess.
it's in the center of Milano, so not too strong wind on it, otherwise big problem,

yeah other-wise...but people sometime is not too much wise...