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1. Why is the technique needed?

Trees and shrubs receive their lifeline from the surrounding area of their rhizosphere. Water and nutrients are absorbed by the finely meshed roots, even the “breathing“ is done by the capillaries in the soil.
This natural cycle is disturbed by soil damaging compactions. This is reflected in loss of vitality and deadwood formation, among other things.
A punctual soil aeration and injection with the VOGT Geo Injector can remedy such a disturbance using compressed air. The compacted soil will be loosened by the injection tube with an adjustable pressure from 5 -8 bar (72-116 psi) and free spaces will be created for the injection material/soil additives. The demolition of fine roots is limited by the pressure regulation. If it happens, however, the soil aeration and the strengthening of the immune system have a positive impact and fine roots will grow in a short time.
Soil damaging compactions are also found in grass areas, event areas, grazing land, paddocks, arable land and in (forests-)kindergarden-outside-playgrounds if soil layers are heavily compacted and the natural gas- and water exchange is disturbed. This can arise when driving, by intensive use or rather frequently entering or through heavy machines during construction activities. One indication for this is that the rainwater seeps badly or doesn’t seep at all and so waterlogging occurs. Here again, the aeration and injection with the VOGT Geo Injector can loosen and remove the soil compaction in order that the natural cycle is given again.

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2. How often and how deep will be aerated?

The aeration will be done by the VOGT Geo Injector, that is placed primary further out from the plant, in the area of the fine roots. Injection in the static (strong-)roots area should be avoided. Therefore, it will be aerated about 1 m inwards and 2 m outwards along the peripheral tree canopy so that the roots can develop to the outside.
The recommended distance between the injection holes is 50 cm for strong compacted or rather loamy soils. For light / sandy soils, the distance can be increased by up to 1 m.
Soil additives will be injected in the roots area at a depth from 30 to 50 cm. The granulate will be put out in two directions, by 90° turning and new output in the same hole the granulates are put out in the other directions. On request, injection tubes with one-sided opening are available.
A pH-value-measurement is recommendable in order to calculate matching soil additives / amounts.
An investigation of the soil layers for soil compaction / waterlogging can be carried out with the help of a hollow chisel (Pürckhaue) in order to identify the problematic soil horizon. A successful aeration and injection is achieved if the compacted soil layer will be loosened and aerated so that the gas- and water exchange can be granted again.
Injection tubes are available in the following lengths: 50 cm, 65 cm, 80 cm, 95 cm, 110 cm, 140 cm, 170 cm, 200 cm.
The injection area must have free access – possibly remove safety cover (tree protection cover). Higher technical effort for aeration of paved or asphalted surface. The injection area has to be free of supply lines.

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3. How high is the average daily output per device?

The daily output depends on different factors. A good work preparation, logistic and a well-rehearsed process lead to a performance increase. A suitable soil humidity is also a very important factor. There are bigger shear forces between the single grains in a dry soil than in a damp soil. The humidity lowers the shear force, so the injection tube can be injected better into the soil and a fine breakup can be rendered at all possible.
For dry soil the injection area should be watered with a watering system 3 days before, for about 3 h daily. The soil, however, should not be too wet, since the capillaries could smear (mud). The soil is optimally workable if he has a stiff or semi-solid texture.
Generally, you can calculate with the following daily output:
VOGT Geo Injector mini: 250 injections per day with a 50 cm deep injection

VOGT Geo Injector maxi: 350 injections per day with a 50 cm deep injection

VOGT Geo Injector pro: 500 injections per day with a 50 cm deep injection

VOGT Geo Injector fluid: 350 injections per day with a 50 cm deep injection

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4. Which amount of air and which compressor is needed?

An effective soil aeration is influenced by two factors. An injection pressure adapted to the soil in combination with sufficient loosening capacity. An undersized compressor / undersized pneumatic hose reduces the loosening capacity and thus the result. Strongly binding / clayey soils have to be aerated with the maximum pressure. We offer compressors with special equipment – specially designed for soil aerating and soil injection with environmentally friendly compressor oil and special pneumatic hoses.

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Typ / Type
Empfohlener Druck / Recommended pressure
Mindestvolumen / Minimum volume
Empfohlenes Volumen mit optimalen Ergebnissen / Recommended volume with optimal results
VOGT Geo Injector mini
5,0 - 8,0 bar / 72 – 116 psi
1,2 m³/min
2,5 – 5,0 m³/min
VOGT Geo Injector maxi
5,0 - 8,0 bar / 72 – 116 psi
2,5 m³/min
2,5 – 5,0 m³/min
VOGT Geo Injector pro
5,0 - 8,0 bar / 72 – 116 psi
2,5 m³/min
2,5 – 5,0 m³/min
VOGT Geo Injector fluid
5,0 - 8,0 bar / 72 – 116 psi
2,5 m³/min
2,5 – 5,0 m³/min
VOGT Lanze / VOGT Air Lance
5,0 - 10,0 bar / 44 – 145 psi
Düse / Nozzle 1: 1,5 –1,9m³/min
Düse / Nozzle 2: 2,0 – 2,9m³/min
Düse / Nozzle 3: 3,0 – 3,9m³/min
Düse / Nozzle 4: 4,0 – 6,0m³/min
Standard: 2,5-3,5m³/min

5. How to transport the needed equipment?

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Variant 1

(depends on authorised load capacity)


  • large distance are quickly accessible

  • short set-up times

  • application is possible up to 10 m directly from the transporter


  • Transporter should be used only for the injection technique


  • long wheelbase

  • reinforced springs

  • sliding doors on both sides


1x Injection technology




Variante 2

(depends on authorised load capacity)


  • compact & all in the trailer


  • watch out for load distribution


  • side or front entrance is needed for
    compressor air circulation


1x Injection technology




Variante 3

(depends on authorised load capacity)


  • no additional investments for vehicle fleet

  • compressor seperately usable


  • high set-up times

  • time requirement for loading and uploading of technique

1x Injection technology




6. Is it possible to place the compressor even further away?

This is possible through the big dimensioned buffer hoses (1 ½“) between compressor and injection device and thus distances of up to 100 m can be spanned.

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7. Which amounts will be injected?

Depends on material and property of the materials.
VGI mini: up to 70 ml per injection, if engaging lever is opened for 2 seconds*. VGI maxi: up to 600 ml per injection, if engaging lever is opened for 2 seconds *. VGI pro: Adjustable amount of injection between 100 – 300 ml per release process*. VGI fluid: Injektionsmenge einstellbar durch Zeitventil.
*These numbers comply with an injection with Terramol.

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8. Which granulates can be used and where can I buy them?

Injectable materials for VGI mini, maxi, pro
Maximum grain size 3 – 4 mm, in dry condition Maximum amount of fines (1 – 3 mm) of 20 %
It is important that the injection holes are heavily watered at the completion of the operations, so the granulate is saturated with water. Otherwise, strongly hygroscopic materials absorb moisture from the area and a negative effect can occur.
Injectable liquid and gel-type suspensions for VGI fluid
Injectable granulates/soil additives can be inquired / sourced e.g. by our partner terra fit These granulates are adjusted according to all VOGT Geo Injectors.

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9. How big is the injection hole and what happens to it?

The injection tube has a diameter of 25 mm and normally leaves an injection hole with this diameter. Afterwards the hole should be filled with a pourable hygroscopic material, thus no fines will be soaked over time and the hole will seal again. Customers have had good experiences with Terramol TE30 K, TE 40 K or TE 50 K, this is a burned diatomaceous earth from natural sources. Through the texture long-lasting horizontal and vertical air channels occur, which function as drainages. The microscopic structure of the material additionally buffers excessive water and nutrients.

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10. How do I calculate the costs for soil injections?

In practice, projects are offered / accounted differently. There is per-diem accounting, daily- or hour flat rate, accounting per injection or square meter or invoicing by tree size / types with a minimum number of trees or injections per each job. Every billing system has advantages and disadvantages and everyone has to decide for himself or rather be clarified with the customer. We will be pleased to help you in providing sample texts for announcements for the private and public area
Following factores have to be considered for the calculation / pricing:

  • Personnel costs and their hourly rates for execution
    Efforts for work in advance like initial customer visit, tendering, material accounting, etc.

    The VOGT Geo Injectors can be handled by one person. In general, two persons are used for the performance, in order to complete the following operations:
    - Clearance / examination by cable finder device, in order to know if the injection area is free of cables. Set up of the devices on site.
    - Handling of the VOGT Geo Injector.
    - Material mixture and refill material.
    - Backfilling of injection caverns with supporting granulate. (e.g. Terramol - no grit or gravel).
    - Traffic and building site protection

  • Machine-cost rate for VOGT Geo Injector
    - Machine-cost rate for Kompressor
    - Costs for operating materials compressor (diesel)
    - Costs for injection material
    - Travel costs

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11. What is relevant for the initial start-up?

The Geo Injector maxi and pro are pressure devices which underlie an acceptance of initial start-up and inspection intervals according to the applicable Industrial Safety Regulation in Germany. We can carry out the commissioning and the periodic inspections in our house in cooperation with the responsible inspection center (ZÜS).
The requirements vary country-specific inside and outside of Europe and have to be cleared with the actually relevant department. All relevant test documents will be delivered with the goods. The vessels are interpreted and certified according to AD-2000 policy. For non-European countries the buffer tanks are available according to ASME-Norm.

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12. How quickly will a positive difference be recognizable?

The specialist will recognize a positive difference for trees by the leaf green, increase in shoot length and the vitality. For laymen it is hard to identify and thus should be shown to a specialist. After one or further vegetation periods it is also clearly recognizable for a layman.

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