This page is written by GEOMAC, and we build a soil-decompaction machine ourselves. So we are not impartial. What follows are the criteria we designed our own machine against; they apply just as well if you end up buying elsewhere. Where we mention the competition, we stick to facts you can verify yourself.
Six points that make the difference
Pressure and air volume need each other
The bar rating tells only half the story: high flow matters just as much. Pressure supplies the breaking force, but the moment the layer opens, air escapes. With too little flow (air volume per minute) the pressure drops away at once; with enough, the pressure spreads further through the soil and the burst is more effective. The high air velocity this creates carries injected material further into the fractures, so you are left with as few plugs or nests of material as possible. So ask not only about working pressure but about the minimum recommended compressor capacity, and count that into your investment: the compressor is usually not included.
Can you inject anything, and how much?
Air alone gives a temporary result. The difference between a treatment that lasts a season and one that genuinely restarts the soil lies in what you send along: granules that hold the fractures open, soil improvers, nutrients. Look at the buffer tank capacity and whether dosing is adjustable. A tank you have to refill every few trees will cost you the day.
Electric or combustion engine
More and more clients, municipalities especially, set requirements on emissions and noise. In a city centre, a cemetery or next to a care home, an electric machine is often the difference between being allowed to work and not. Consider the working day too: no exhaust fumes beside your own head, and considerably less noise.
Can you even reach the work?
The work is rarely in an open field. Back gardens, courtyards, tree pits between parked cars: width and weight decide whether you can take the job at all. Check whether the machine fits through a standard gate and doorway, what it weighs, and how far the lance reaches from the unit. That working radius determines how often you have to move the whole machine.
How do you transport it?
A machine that only fits on a trailer behind a heavy van changes your planning and your licence requirements. If it is light enough for the vehicle you already run, that saves time every single day. Work this out before you look at the price.
Who do you call when it stops?
This is the point that appears on no specification sheet and hits you hardest. If the machine stops on a Monday with a full week behind it, what counts is how quickly someone who genuinely knows it can be there, and whether the part is on a shelf or has to cross a border first.
Are you buying from the maker or from an importer?
In this market that is a real distinction. Most machines you will come across are built abroad and reach the customer through a distributor.
The VOGT Geo Injector is built in Germany and reaches the Netherlands through a distributor; the Air2G2 is built in the United States and reaches customers through dealers. That can work perfectly well, with specialists who know the product.
What you do want to ask: where are the parts held, and who decides if something needs to change structurally? A suggested improvement has a longer road to travel.
GEOMAC designs, develops and builds the machine in Ederveen and supplies it directly. Service and parts come out of that same workshop.
Call with a problem and you reach the people who built it. If a fault recurs, the next build is changed, because we run the machine ourselves.
When does your own machine pay for itself?
There is no fixed figure, and anyone who gives you one is guessing. What drives the sum can be named, though. Put these four side by side and you will know enough:
Days per year you currently subcontract or hire this work in.
What hiring in costs per day, including travel and waiting time.
Jobs you currently turn down because you cannot do them yourself.
Do you already have one that delivers enough, or does it come on top?
The third is the one most often forgotten and the one that weighs heaviest. Arborists who start offering root-zone improvement usually sell it to clients they already have. Ask for pricing and we will set it out for your situation.
Frequently asked questions about choosing a machine
What does a soil-decompaction machine cost?
At GEOMAC the price is on request, because it depends on the configuration: the length of the lance and the accessories you choose. Budget for a compressor as well if you do not yet have one that delivers enough; it does not come with the machine. Get in touch and we will set it out for your situation.
Do I need a certificate or training to operate one?
There is no legally required certificate for the decompaction itself. What does count is soil knowledge: moisture content and soil structure largely determine what a burst of air will do. Always establish where cables and pipes run before you start.
Can I try a machine first?
At GEOMAC you can request an on-site demonstration: you work in your own ground and feel how the machine steers and how quickly you are set up. That tells you more than any specification sheet, precisely because soil differs from site to site.
Is a second-hand machine a good idea?
Supply is small, because there are not many of these machines about. If you do find one, look closely at the wear parts that meet compressed air and injected material, and check whether parts and service are still available for it. A cheap machine nobody will work on is expensive.
See it in your own soil.
Ask for pricing or an on-site demonstration, direct from the manufacturer.