Soil compaction

[Will Hinchliffe]

It is my understanding that Airspades can potentially pulverise the soil destroying the peds. Fine roots can also be desicated in the process and michorhizal associastions effected.

 

Bulk density analysis should show you the layers of the soil that are compacted. Mulching may work to relieve top soil compaction but the soil will remain susceptible to further compaction so you have to limit access to the rooting zone and it will do little to relive compaction of the sub soil.

 

I think Lee's suggestion of radial trenching is an excellent solution to compaction. It deals with top soil and sub soil compaction, can be carried out without the need for expensive tools (although they may make the job easier and more profitable) and provides the tree with more available rooting area and fresh soil loaded with nutrients.

 

When radial trenching is done well studies have shown the trenches to become full of feeding roots from the tree.

[Lee Winger]

Giles I use the Air-spade to create holes for vertical mulchiing, we can achieve holes of up to 18'' depending on compaction and soil type.......

[Lee Winger]

It is my understanding that Airspades can potentially pulverise the soil destroying the peds. Fine roots can also be desicated in the process and michorhizal associastions effected.

 

Bulk density analysis should show you the layers of the soil that are compacted. Mulching may work to relieve top soil compaction but the soil will remain susceptible to further compaction so you have to limit access to the rooting zone and it will do little to relive compaction of the sub soil.

 

I think Lee's suggestion of radial trenching is an excellent solution to compaction. It deals with top soil and sub soil compaction, can be carried out without the need for expensive tools (although they may make the job easier and more profitable) and provides the tree with more available rooting area and fresh soil loaded with nutrients.

 

When radial trenching is done well studies have shown the trenches to become full of feeding roots from the tree.

 

Organic matter rules.....

[Mark T]

I had a site about 5 years ago where there was extensive compaction and mechanical root damage, in all about 40 mature trees were affected. In an attempt to save the trees I treated a proportion of the affected rooting areas with the terravent and the rest were verti-mulched (holes backfilled with well rotted OM). I thought at the time that it might make an interesting case study...

 

To date, I have re-visited the site 3 times to briefly assess the condition of the trees affected and I'm amazed to see how well they're doing - especially as I thought that the damage was so extensive, major losses were on the cards!

 

Here are a few pics of the site and terravent will upload some of the Verti-mulch setup later...

[Lee Winger]

Unfortunatly 5 years isn't that much time in the life of a tree Gimmer as you know, some rather extensive root damage there mate, fingers crossed for the future...

[Mark T]

I nearly dropped my bacon roll when I walked round the corner and saw that trench - that was the tip of the iceberg too!

 

You're right Lee, 5 years is nothing really... It'll be really interesting to see what'll happen. Fingers crossed!

[Xerxses]

I have the Soil-pick, Air-spade and deep root aerator. The soil-pick and Air-spade are great tools for removing top layers of compacted soil away from tree roots for IE root inspections , root pruning etc etc.

 

IMO they aren't that good at general de-compacting, as you can't remove soil much more than 12'' deep because gravity sends the soil back into your hole, and the only soil vac I've found costs over 20k and the only ones for hire are in the West country and charge a 1k a day..

 

If I could talk people into it i'd go with vertical mulching everytime and general soil de-compaction using the deep root aerator,and let the bugs and worms do the rest, but the trouble is some people don't like the look of mulch so you can't win lol, saying that I did find a client last week , who cared more about the tree than the lawns appearance..

 

Here are a few pics from a recent job

 

"deep root aerator" is new to me how does it work? pics and info would be appreciated...

[Bundle 2]

"It is my understanding that Airspades can potentially pulverise the soil destroying the peds. Fine roots can also be desicated in the process and michorhizal associastions effected....."

 

Im not sure about pulverising the soil as such but certainly it alters the structure.....Embollism being introduced has been discussed I know and undoubtedly, mycorrizhal assoc' may well be affected. As for dessication, these fine root hairs are I believe quite quickly regenerated.(Oops...generalisation....)

Glynn repeated his assertion that the airspade is effective against honey fungus again today.....

Pretty much think the terravant is next to useless and may infact make compaction worse by simply lifting layers of the soil profile and dumping it down again . Limited experience myself but it kinda makes sense.....

 

"Like I said in my last post , radial trenching or vertical mulching is my preferred method, but some wont have it and so out comes the deep root aerator........"

Makes sense I guess....like Xerxses...what is it ?

[Lee Winger]

DRA It's a tube thats pneumatically knocked into the soil, you open a valve and compressed air rushes out, creating fissures, nothing too exciting....

Edited June 4, 2009 by Lee Winger

[ScottF]

DRA It's a tube thats pneumatically knocked into the soil, you open a valve and compressed air rushes out, creating fissures, nothing too exciting....

 

I'd love to see it working, Lee. Let us know if you're ever working in Mid or North Wales.

 

Sounds interesting.

 

I've used Terravent machines in Canada for years and found them very effective, used correctly.