Test: McConnel Shakaerator

By: Jaiden Drought, Photography by: Jaiden Drought

For farmers, the McConnel Shakaerator ticks many boxes. It's pocket-friendly and, generally, you won't have to invest in another tractor to pull. Farm Trader reviews.

Soil compaction is a costly issue in most developed agricultural countries. There are a few reasons for this. Firstly, machinery has become significantly larger and heavier as we search for improved efficiency, and secondly, improved technology and livestock genetics allow more cows or crops per hectare.

As the need to extract more dollars per hectare continues, farmers often push the soil to its limits, grazing more cattle and more intensively, grazing high-yielding crops in situ, and using tillage in poor soil conditions. While this may give a ‘quick fix’ to the balance sheet, in most cases it ends up detrimental in the long run, reducing the quality of soil, its moisture holding capacity, and micro-organism activity.


Now, I am not a ‘greenie’, but I am a farmer who wants to see a prosperous farming future for the following generations. The weather has become extreme in New Zealand and combined with the massive intensification of farms (driven by land prices), the high debt per hectare means more cattle per hectare are run on a more intensive system in order to pay the bank. Extreme wet and dry weather soil is damaged, but in an almost full circle problem, this reduced soil performance and reduced stock carrying capacity see farmers having to buy more food or fertiliser to keep up production.

It’s a vicious circle with no winner. Mechanical aeration is a big business in Europe, both on cropping ground and in pastural farming. To date in New Zealand, it is mainly used as a cropping tool. Many will remember the old groundhog spiked roller, which provided aeration but six inches often didn’t break up the major subsoil pan.

I recently spent time with Trevor Gooch, a Taranaki dairy farmer who operates 63 hectares with his wife in Midhurst. This is Taranaki’s version of the West Coast of the South Island – often wet.

Early last season, Trevor invested in a 2.5-metre version of McConnel’s Shakaerator. He has since been impressed not only by the performance of the machine but also the increased grass growth due to improved soil health.

How does the Shakaerator work?


Like many aerators, simplicity is the key to the design. A leading disc coulter cuts a slit, and a well-shaped leg then moves and shatters the soil upwards. This breaks up any soil compaction and allows space for roots to grow and moisture to move through the soil profile. Any surface disturbance is smoothed out with a flat (possibly water filled) rear roller.

The key to McConnel’s Shakaerator is its PTO-driven vibration unit. This does two things. First, it dramatically reduces the power requirements, as the vibration allows enough movement to help propel the machine forward, and second, the entire machine shakes up and down as well as side to side as it slices through the ground. This shattering action breaks up the soil of any compaction.

The other major benefit of the 2.5-metre three-leg machine is the 830mm gap between the legs. This shakes an additional 830mm on the outside of the machine between the slots in the ground of the previous pass. In fact, in pasture, 3.3 metres is a more accurate working width (2.5-metre machine width plus additional .83 metres on the outside), allowing 1.5–2 hectares per hour with Trevor’s 97hp tractor at 6km/hr.

Shear bolt protection proves effective for the legs. Trevor has never broken one and we didn’t break one during our test (if something’s going to go wrong, we generally discover it in our test conditions!). Last year, Trevor did normal runs the length of the paddock. This year, he’s doing it crossways to give the soil a tune-up. Turning is generally a no-no, so runs are the preferred method. At the end of a run, you simply switch off the PTO and back up a couple of feet while lifting the machine out of the ground. This results in minimal turf disturbance.

Does it work? The short answer is yes. Although not strictly scientific, Trevor has several observations along with soil profile diggings, which have impressed him.

Since Trevor has owned this machine, Taranaki has had the wettest winter many can remember, followed by the longest drought in 50 years, so water movement through the soil profile has been extremely important.

Benefits in the wet


After digging soil profile holes after several rain events, once the Shakaerator has been through the paddock, for every 1mm of rain, the water makes its way down 4mm in the soil.

Last winter and spring was one to forget for many. Those with already compacted soil reduced oxygen in the soil, which allows water and nutrients to move more freely around the soil profile. Compacted soil has reduced porosity, so takes less water to reach maximum saturation. Once this occurs, the worms have nowhere to go but simply die lying on the surface.

In particularly wet conditions, Trevor has seen that the water does run down the slots. This helps with drainage and also results in the soil profile being moved around and vibrated, allowing the water holding capacity of the soil to be significantly higher at much greater depth.

Benefits in the dry


In dry conditions, better soil porosity allows water to come back up to the root zone, as the pan has been broken up. The shaking also moves the soil profile around, which creates more space for air and water to sit in rather than just sitting on top of a pan. This means water and nutrients are present in the ‘root zone’ for longer, so your pasture or crop has reduced stress waiting for the next rain event.

Another observation is a significant reduction in summer pasture weeds due to the grass being thicker and the roots being deeper. This allows grass to be more persistent year-round in both wet and dry conditions.



For farmers, this machine ticks many boxes. It doesn’t cost the earth, it doesn’t cost a huge amount to run, generally, you won’t have to invest in another tractor to pull it, and the ha/hr rate is quite achievable.

There are not a lot of negatives given the substantial increases in both drainage and water holding capacity for soil, aiding grass growth and persistence while reducing summer weed population without the use of chemicals smashing the clover around.McConnel also offers a narrow vineyard/orchard version called the ‘Fruitaerator’, which has the same mechanical concept and soil health benefits, with reduced working width and horsepower, as smaller tractors are generally used.


  • Reduction in soil pan has a huge increase in pasture persistence and performance
  • Unique vibration action
  • Low power requirements
  • Range of working width and leg options
  • Optional auto reset legs for challenging soil conditions
  • Adjustable pivoting leading discs
  • Smooth rear roller allows depth adjustment
  • Replaceable ‘knock off’ points
  • High work rates given working width
  • High build quality, low maintenance – perfect for farmers


  • Good way to find all your nicely buried water lines

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