has anyone ever used an air spade?

bigshea13 · 14th January 2008, 10:41 AM

ive got a few trees that the homeowners{my grandparents} have repeatedly driven around and over the years the soil has become so compact that the water is unable to penetrate . the soil has become like rock. iwant to fabricate an air spade to remove the old soil and replace it with mulch and new soil. so i guess what i want to know is should keep soil moist when spading and what shouldnt i do with it? how many psi is standard for them. the trees are apples 10- 15 YRS old. my intentions are to stabilize the trees before the process, spade, refill...{do i compress soil at all or just water} then mulch. they are fairly broad so im also wondering if this should be doneall at once or a little at a time.

Sean Freeman · 14th January 2008, 01:01 PM

bigshea I've used the homemade variety, we used our own to decompact, vertically mulch and tried using it to cut trenches around transplants.

The main problem with homemade is the lack of proper nozzle....the superrsonic nozzles ramp up the force with which the air hits the soil and thereby the effectiveness of the tool as a whole. We also encountered some issues with ours relating to wear and tear around the trigger and handle, where it attaches to the wand....this can be a weak point especially since some leverage motion is almost inevitable even with very careful operations.

We operated ours at a range of pressures and nozzle diameters found that a compressor working around 180cfm and a nozzle diameter of 8mm worked best for us.

Always try to have the area irrigated 24hrs before the work...makes it much easier and quicker...as well as less stressful for the operator, reduces the volume of fine particles flying out at high speed!
Always have appropriate ppe, face shield thick pants gloves helmet etc.

The very best results we had came from decompaction through good quality mulch after irrigation. There is always a question as to just how much difference decompaction and even vertical mulching actually does...to be honest with you the scientific evidence suggests not much! But since every tree and its soil environment is unique even the best studies are really only specific to that tree in those conditions. As I say through well composted woodchip mulch after irrigation it is a great way to enhance the soil-root environment especially when it has been badly compacted.

One last point it is a tremendously useful tool for examining root crowns especially when you are concerned about the extend of decay in buttress roots..valuable trees or high value targets.

treevet · 14th January 2008, 03:03 PM

I agree with what Sean said about inspecting buttress roots or root crowns for various reasons. I just think if you want to aeriate or refract compacted soil why not used compressed water (spray rig/feed gun)? Dry out roots or moisten them? When the water is used or disapates or transpires the soil should be less compacted. As for soil ammendments, an earth auger on a Tanaka drill doing vertical mulching seems much easier for improving soil quality. As you mentioned what do you do with all the displaced soil? I ve used one a number of times and they make a huge mess and a tremendous amount of noise and would catagorize them as a gimmick in this application.

TreeDimensional · 15th January 2008, 12:04 PM

bigshea13, don't you folks there get the freeze/thaw thing going on? Or are you speaking of compaction due to use(foot traffic or vehicle). I assume that an air-spade @ 180 psi would need a screw compressor, am I correct?

Gilman has a powerpoint on the benefits of verticle trenching, and it appears to me that if a tree is in an anerobic setting for the roots, the trenching could do nothing BUT good. Coder also went to great lengths to explain that in his part of the world (Georgia), with adequate moisture, you only have to step in the same footprint 3 times before you reach maximum compaction. If I were to adopt this as true, I would have to assume that for the benefit of the trees, I should consider adopting the same policy of prevention for residental trees as I would for tree preservation at a construction site.

In the thread on trees and sewer lines, the process of a tree sending roots into a relatively oxygen deficient enviornment, in the search of water, prompted some additional thought on my part. I remembered that a friend of mine was looking for the tree that caused the sewer line to back up. There was $300,000 worth of damage, and about 75 suspects to look at. In the end they determined that they had found the guilty tree, it was the closest tree adjacent to the trench for the sewer line. I guess that time will tell, but he indicated that when they were grinding the stump, they noticed a more than usual number of grafted roots. Moral of the story, the sewer trench was less compacted (even after 40 years of abuse) than the surrounding soil.

This is the readers digest version, the whole story is better, but this thread has nothing to with genetically identifying the main sewer line instigator, but might be food for thought, OR not.

To answer shea's question: No I haven't used an air-spade, the cost of buying or renting a screw compressor would push the price out of the tree owners comfort zone. Another thing is that if the spade was only for exposing the root flair, would indicate to me that the tree was either planted too deep or some landscape Co. applied too much backfill (grade change). I think there are more productive ways to improve soil structure than blowing dirt all over the neighborhood.

Ekka · 16th January 2008, 02:23 AM

Sean said they use a 180cfm compressor not 180psi.

You need a huge volume or capacity to have a continual blast of air running out of a 5/16" hole.

I have a large domestic compressor that can crank 140psi but it only has 13cfm capacity so I run out of air fast and the pump is going flat out.

A 180cfm compressor is one of those petrol driven jobs you tow around with the big fat hoses, you need that for the volume of air that will be going through your air spade.

Would be a messy job and off the record I heard on the grape vine that decompacting is down the line from mulching ... some prefer to see you mulch rather than fragment the root system as the soil fractures many of the finer roots will be broken as they are attached to the soil. But in saying that if you have a compacted surface you cannot mulch then you dont have many choices than to decompact.

Watering will add to compaction if weight is put on by traffic/people etc afterwards.

Sean Freeman · 16th January 2008, 04:45 AM

Eric's right its a trail behind compressor with big hoses, noisey and yes messy with the dirt thrown out. As I tried to suggest there is little scientific evedence to demonstrate decompaction does very much at all...in fact the few studies that have been published in peer reviewed journals show no difference from the control in the measurements taken.

Personally I think its another case of one size does not fit all, or rather one element does not meet all needs.....mulch, water then decompact then drench with the combination of goodies determined from your comprehensive soil tests....that combination provides the best of all worlds.

treeseer · 16th January 2008, 06:38 PM

Quote:

Originally Posted by Sean Freeman

Eric's right its a trail behind compressor with big hoses, noisey and yes messy with the dirt thrown out. As I tried to suggest there is little scientific evedence to demonstrate decompaction does very much at all...in fact the few studies that have been published in peer reviewed journals show no difference from the control in the measurements taken.

Sean, there are also studies with positive results (see the Tienanmen Square work), but as you say it is site and tree dependent; many variables. Yes the air tool does mess up small roots--the size that the tree can regrow quickly. Drills go through roots big and small, and glaze the sides of the holes, greatly reducing permeability in some soils.

treekiwi · 17th January 2008, 07:36 PM

Hey guys,
my previous company used 3 airspades with success. We used a portable tent when airspading and blew the dirt into trays to get ride of it. The airspade is designed to not damage the major root system and blows the dirt away from roots even very small tracer roots. Another suggestion is the aplication of a grow-gun when is effectively used to lift the soil through the application of water an compressed air through a probe. This could be a good sugggestion instead of airspading and removing the soil.

bigshea13 · 17th January 2008, 08:46 PM

Quote:

Originally Posted by treekiwi

Hey guys,
my previous company used 3 airspades with success. We used a portable tent when airspading and blew the dirt into trays to get ride of it. The airspade is designed to not damage the major root system and blows the dirt away from roots even very small tracer roots. Another suggestion is the aplication of a grow-gun when is effectively used to lift the soil through the application of water an compressed air through a probe. This could be a good sugggestion instead of airspading and removing the soil.

i may attempt something similar to that instead of the air spade, i wasnt aware of the pressure required, plus the duration. i was hoping to hear that the design of one was a little simpler. gettin the psi that high wouldnt be the prob but keeping it there would be...at least with something semi portable. i was thinking along the lines of a hydro/airator contraption. along the same lines as when you blow into a straw thats at the bottom of your milkshake and it bubbles. i dunno. ive got several months to think it over.

Ekka · 17th January 2008, 09:12 PM

Quote:

Originally Posted by treeseer

Sean, there are also studies with positive results (see the Tienanmen Square work), but as you say it is site and tree dependent; many variables. Yes the air tool does mess up small roots--the size that the tree can regrow quickly. Drills go through roots big and small, and glaze the sides of the holes, greatly reducing permeability in some soils.

I'll remember that next time a protest gets broken up with tanks, thanks.

Sean Freeman · 17th January 2008, 10:25 PM

Quote:

I'll remember that next time a protest gets broken up with tanks, thanks.

Ok thats mean but very funny

Therrin · 18th January 2008, 08:43 PM

At one location I was going to arrange for putting in mulching for a line of trees along a road. The soil around them is pretty compacted, and is what we call "decomposed granite". It packs in pretty good.

These trees are only a couple years old. I'll find out the types and take pictures in the next couple days.

The question, is how do you take out compacted soil around the base of the trunk, in order to put mulching in around it? You'd use one of these air spades?

I was considering doing something with high pressure water, set a little tent around it to reduce splatter, dig for drainage. You might not be able to do that in some locations, but here I can. Would the Air Spade be better for this, or would high-pressure water work too?

treeseer · 19th January 2008, 03:35 AM

Quote:

Originally Posted by Sean Freeman

Ok thats mean but very funny

I don't get it.

newguy18 · 19th January 2008, 08:42 PM

i know it could chew roots if one wasn't careful but could you use a mantis mini tiller to break the soil loose?

treekiwi · 20th January 2008, 12:54 AM

Hi Guys,
yea we used a portable diesel powered air compressor and a long hose, with the grow gun you used the same sort of pressure with the application of water plus fertiliser if required when the air spaces become avaliable, good method but can be time consuming, make sure you use a hourly rate...

Ray stump man · 24th January 2008, 07:16 AM

Quote:

Originally Posted by Sean Freeman

14th January 2008, 10:41 AM	#1 (permalink)
bigshea13 Mature tree Join Date: Nov 2007 Location: hiding Posts: 386	has anyone ever used an air spade? ive got a few trees that the homeowners{my grandparents} have repeatedly driven around and over the years the soil has become so compact that the water is unable to penetrate . the soil has become like rock. iwant to fabricate an air spade to remove the old soil and replace it with mulch and new soil. so i guess what i want to know is should keep soil moist when spading and what shouldnt i do with it? how many psi is standard for them. the trees are apples 10- 15 YRS old. my intentions are to stabilize the trees before the process, spade, refill...{do i compress soil at all or just water} then mulch. they are fairly broad so im also wondering if this should be doneall at once or a little at a time.

14th January 2008, 01:01 PM	#2 (permalink)
Sean Freeman PDF King & Arborist Extrodinaire Join Date: Feb 2007 Location: Townsville Nth Queensland & Gold Coast Sth Queensland Posts: 1,649	Re: has anyone ever used an air spade? bigshea I've used the homemade variety, we used our own to decompact, vertically mulch and tried using it to cut trenches around transplants. The main problem with homemade is the lack of proper nozzle....the superrsonic nozzles ramp up the force with which the air hits the soil and thereby the effectiveness of the tool as a whole. We also encountered some issues with ours relating to wear and tear around the trigger and handle, where it attaches to the wand....this can be a weak point especially since some leverage motion is almost inevitable even with very careful operations. We operated ours at a range of pressures and nozzle diameters found that a compressor working around 180cfm and a nozzle diameter of 8mm worked best for us. Always try to have the area irrigated 24hrs before the work...makes it much easier and quicker...as well as less stressful for the operator, reduces the volume of fine particles flying out at high speed! Always have appropriate ppe, face shield thick pants gloves helmet etc. The very best results we had came from decompaction through good quality mulch after irrigation. There is always a question as to just how much difference decompaction and even vertical mulching actually does...to be honest with you the scientific evidence suggests not much! But since every tree and its soil environment is unique even the best studies are really only specific to that tree in those conditions. As I say through well composted woodchip mulch after irrigation it is a great way to enhance the soil-root environment especially when it has been badly compacted. One last point it is a tremendously useful tool for examining root crowns especially when you are concerned about the extend of decay in buttress roots..valuable trees or high value targets. __________________ Sean Trees are poems that earth writes upon the sky, We fell them down and turn them into paper, That we may record our emptiness. - Kahlil Gibran

14th January 2008, 03:03 PM	#3 (permalink)
treevet Over mature heritage tree Join Date: Dec 2007 Location: Cincinnati, Ohio, USA Posts: 823	Re: has anyone ever used an air spade? I agree with what Sean said about inspecting buttress roots or root crowns for various reasons. I just think if you want to aeriate or refract compacted soil why not used compressed water (spray rig/feed gun)? Dry out roots or moisten them? When the water is used or disapates or transpires the soil should be less compacted. As for soil ammendments, an earth auger on a Tanaka drill doing vertical mulching seems much easier for improving soil quality. As you mentioned what do you do with all the displaced soil? I ve used one a number of times and they make a huge mess and a tremendous amount of noise and would catagorize them as a gimmick in this application.

15th January 2008, 12:04 PM	#4 (permalink)
TreeDimensional Banned Join Date: Feb 2007 Location: Canada Posts: 385	Re: has anyone ever used an air spade? bigshea13, don't you folks there get the freeze/thaw thing going on? Or are you speaking of compaction due to use(foot traffic or vehicle). I assume that an air-spade @ 180 psi would need a screw compressor, am I correct? Gilman has a powerpoint on the benefits of verticle trenching, and it appears to me that if a tree is in an anerobic setting for the roots, the trenching could do nothing BUT good. Coder also went to great lengths to explain that in his part of the world (Georgia), with adequate moisture, you only have to step in the same footprint 3 times before you reach maximum compaction. If I were to adopt this as true, I would have to assume that for the benefit of the trees, I should consider adopting the same policy of prevention for residental trees as I would for tree preservation at a construction site. In the thread on trees and sewer lines, the process of a tree sending roots into a relatively oxygen deficient enviornment, in the search of water, prompted some additional thought on my part. I remembered that a friend of mine was looking for the tree that caused the sewer line to back up. There was $300,000 worth of damage, and about 75 suspects to look at. In the end they determined that they had found the guilty tree, it was the closest tree adjacent to the trench for the sewer line. I guess that time will tell, but he indicated that when they were grinding the stump, they noticed a more than usual number of grafted roots. Moral of the story, the sewer trench was less compacted (even after 40 years of abuse) than the surrounding soil. This is the readers digest version, the whole story is better, but this thread has nothing to with genetically identifying the main sewer line instigator, but might be food for thought, OR not. To answer shea's question: No I haven't used an air-spade, the cost of buying or renting a screw compressor would push the price out of the tree owners comfort zone. Another thing is that if the spade was only for exposing the root flair, would indicate to me that the tree was either planted too deep or some landscape Co. applied too much backfill (grade change). I think there are more productive ways to improve soil structure than blowing dirt all over the neighborhood. Last edited by TreeDimensional : 15th January 2008 at 02:55 PM. Reason: content

16th January 2008, 02:23 AM	#5 (permalink)
Ekka Eric Frei Administrator - Brisbane L5 (Dip) Hort Cert III Arb + some Join Date: Jan 2007 Location: Brisbane Posts: 6,606	Re: has anyone ever used an air spade? Sean said they use a 180cfm compressor not 180psi. You need a huge volume or capacity to have a continual blast of air running out of a 5/16" hole. I have a large domestic compressor that can crank 140psi but it only has 13cfm capacity so I run out of air fast and the pump is going flat out. A 180cfm compressor is one of those petrol driven jobs you tow around with the big fat hoses, you need that for the volume of air that will be going through your air spade. Would be a messy job and off the record I heard on the grape vine that decompacting is down the line from mulching ... some prefer to see you mulch rather than fragment the root system as the soil fractures many of the finer roots will be broken as they are attached to the soil. But in saying that if you have a compacted surface you cannot mulch then you dont have many choices than to decompact. Watering will add to compaction if weight is put on by traffic/people etc afterwards. __________________ Remember to use the "search" function, if you have answers/questions post them so everyone can benefit. Free Tree and Green Industry Link Directory Qualified Brisbane Tree Lopping Brisbane Tree Care, Consultations and Arborist Reports Forum Sponsors

16th January 2008, 04:45 AM	#6 (permalink)
Sean Freeman PDF King & Arborist Extrodinaire Join Date: Feb 2007 Location: Townsville Nth Queensland & Gold Coast Sth Queensland Posts: 1,649	Re: has anyone ever used an air spade? Eric's right its a trail behind compressor with big hoses, noisey and yes messy with the dirt thrown out. As I tried to suggest there is little scientific evedence to demonstrate decompaction does very much at all...in fact the few studies that have been published in peer reviewed journals show no difference from the control in the measurements taken. Personally I think its another case of one size does not fit all, or rather one element does not meet all needs.....mulch, water then decompact then drench with the combination of goodies determined from your comprehensive soil tests....that combination provides the best of all worlds. __________________ Sean Trees are poems that earth writes upon the sky, We fell them down and turn them into paper, That we may record our emptiness. - Kahlil Gibran

17th January 2008, 07:36 PM	#8 (permalink)
treekiwi Semi-mature vigorous tree Join Date: Nov 2007 Location: New Zealand Posts: 100	Re: has anyone ever used an air spade? Hey guys, my previous company used 3 airspades with success. We used a portable tent when airspading and blew the dirt into trays to get ride of it. The airspade is designed to not damage the major root system and blows the dirt away from roots even very small tracer roots. Another suggestion is the aplication of a grow-gun when is effectively used to lift the soil through the application of water an compressed air through a probe. This could be a good sugggestion instead of airspading and removing the soil.

18th January 2008, 08:43 PM	#12 (permalink)
Therrin The Tree World Bandit Join Date: Oct 2007 Location: Lancaster, Ca Posts: 1,255	Re: has anyone ever used an air spade? At one location I was going to arrange for putting in mulching for a line of trees along a road. The soil around them is pretty compacted, and is what we call "decomposed granite". It packs in pretty good. These trees are only a couple years old. I'll find out the types and take pictures in the next couple days. The question, is how do you take out compacted soil around the base of the trunk, in order to put mulching in around it? You'd use one of these air spades? I was considering doing something with high pressure water, set a little tent around it to reduce splatter, dig for drainage. You might not be able to do that in some locations, but here I can. Would the Air Spade be better for this, or would high-pressure water work too? __________________ Ken Fessia I.T.S.A. Tree Service (661) 916-4703

19th January 2008, 08:42 PM	#14 (permalink)
newguy18 Part of the Furniture Join Date: Jun 2007 Location: Live Oak Florida home of the crapiest trees you will ever see. Posts: 2,632	Re: has anyone ever used an air spade? i know it could chew roots if one wasn't careful but could you use a mantis mini tiller to break the soil loose? __________________ Have your say join us today. http://www.youtube.com/watch?v=Xzkd_m4ivmc http://www.youtube.com/watch?v=Xzfzb...eature=related http://www.youtube.com/watch?v=x-OqK...eature=related

20th January 2008, 12:54 AM	#15 (permalink)
treekiwi Semi-mature vigorous tree Join Date: Nov 2007 Location: New Zealand Posts: 100	Re: has anyone ever used an air spade? Hi Guys, yea we used a portable diesel powered air compressor and a long hose, with the grow gun you used the same sort of pressure with the application of water plus fertiliser if required when the air spaces become avaliable, good method but can be time consuming, make sure you use a hourly rate...