SAM six tonne spreader review

Jaiden Drought checks out the SAM six tonne fertiliser spreader, a machine that can handle one of the most corrosive work environments on the farm and still come up good year after year.

Many things are considered farming institutions in New Zealand – including our ability to fix anything with either baling twine or No8 wire, black singlets, Toyota Hilux’s and Red Bands (now also available in jandle and work boot form). This also crosses over into the machinery world with SAM spreaders being right up there.

Having been in the business of making fertiliser spreaders for 56 years, Coombridge and Alexander first launched the SAM spreader in plain red, then switched to the more familiar green and yellow in 1991. In 2005, the plastic hopper version in the same livery, took over from the traditional steel bin.

Coombridge and Alexander, nestled in the heart of the Waikato, has been in the manufacturing business since 1940. It started out making posts but switched to farm machinery in 1946 and hasn’t looked back. The company also offers a wide range of tip trailers and feed out wagons and, given Kiwi farmers reputation for ‘looking after’ equipment and the corrosive nature of fertiliser spreading, it is a testament to its engineering that the 80’s vintage machines are still in operation.

Working features

The test machine is a 2015 six-tonne 400mm belt spreader with swivel coupling, 400/60-15.5 tyres (both standard on six-tonne machines). Optional extras include remote greasing, road lighting and roll top cover. Load cells or the optional fully hydraulic setup and an 800mm-wide belt for organic material are other available options.

Although linkage mounted machines may offer improved spreading accuracy over trailed fertiliser spreaders, they do have one major downfall – capacity, and that is where the trailing SAM spreader will eat it up in terms of hectares. SAM also offers the option of a fully hydraulic drive through a Whitehead Computer Controller with full GPS and section control capabilities, and load weigh scales for operators looking for greater measurement of application rates and product use.


Set up and spreading

The machine simply runs two hoses from the tractor; red is pressure while yellow is return, allowing the 35L/min minimum oil flow to be delivered to the twin 600mm spreading discs to ensure they spin at the desired 850rpm.

To set the desired rate, there is a spreading chart at the back of the spreader while a more comprehensive manual is supplied in the book. You can work out the density of the fertiliser you are spreading if it is a specific blend and match up the spreading rate in the book to have the most accurate results from the back door jack setting.


The floor belt has an in/out clutch that is activated automatically when the spool for the hydraulic spinners are started. To start the hydraulic spinners and engage the clutch, pressurise the live (red) hose. This will place the clutch into gear and subsequently start the hydraulic spinners turning. To stop the hydraulic spinners and place the clutch out of gear, move the hydraulic lever to ‘pressurise’ the return (yellow) hose for one second then place the lever to neutral or float.


Below are the capacities for the test machine although four-, five-, eight and nine-tonne machines are also available with various options and tyre sizes available.

Six-tonne fertiliser spreader (4.6m3)

  • 6t of Superphosphate (1.3t/m3 density)
  • 7.7t of Lime (1.7t/m3 density)
  • 3.7t of Urea (0.8t/m3 density)

Rates, centres and accuracy

Again, the door setting sticker and book chart show the spreading rate at certain centres. It is easier to spread at closer centers (the center of the tracks up and down the paddock) as you can see where you have been and judge the distance more accurately (if not using GPS).

Rates range from 45kg/hectare at 15m spreading centers for nitrogen products all the way up to 3000kg hectare at 10m spreading centers for materials such as lime.


The verdict

The key for any investment in your business is to weigh up the options and decide what’s best for your situation. Yes there are slightly more accurate machines on the market but would the extra four- to five-tonne capacity suit you more?

For many, the answer will be yes. Given SAM’s reputation is built on 35 years of building quality machines that have stood the test of time in what must be one of the most corrosive of conditions, it really is testament to these Kiwi icons and should leave you in no doubt that you’ve purchased a solid product.


  • Well recognised and established brand in New Zealand.
  • Very well built.
  • The mix of plastic, well coated steel and stainless steel to handle its corrosive work environment.
  • Requires only one hydraulic bank from the tractor.
  • Tows very well, is stable in the hills and is easy to get in and out of gateways.
  • Remote greasing means all nipples on the machine are lubricated – no excuse.
  • Oil bath for the main drive chain should ensure years of service.


  • The cover itself works well with the central support beam but I would personally prefer it side mounted, out of the dust, at the rear of the machine.

Read the full article in the latest issue (#227) of Farm Trader magazine. Subscribe here.

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