The literal meaning of 'rocks gone'

Tractor operator Jeremy Thompson (left) and Calingi farmer Ashley King survey a 'reefinated' paddock ready for seeding.
Tractor operator Jeremy Thompson (left) and Calingi farmer Ashley King survey a 'reefinated' paddock ready for seeding.

IT doesn't take long for rocks to become the subject of conversation when you're speaking with most farmers.

And in Western Australia, lateritic soils exist throughout most of the Wheatbelt, rendering typical ironstone country almost non-croppable, with literally thousands of rock patches or rock outcrops that farmers simply go around.

Calingiri farmer Ashley King can relate, noting a ryegrass nursery on a 15 hectare patch of sheeted gravel rock that existed on his property four years ago.

"We got the Rocks Gone guys in with their Reefinator and they cleaned it up and we grew a crop on it the following year," Mr King said.

"Before that it just bred ryegrass.

Needless to say Mr King is rapt in the machine and bought a 200 Series model three years ago to rejuvenate other rocky areas of the farm, which has loam gravels and duplex gravel soils.

"We also decided to renovate out pastures and in one paddock we spread two tonnes a hectare of lime sand and 5t/ha of compost out front," he said.

"Then we used the Reefinator to mix it all in.

"That was two years ago when we got good rain and the paddock of wheat yielded 5.8t/ha.

"I never seen that in my life and there was no ryegrass.

"Last year in another paddock that we reefinated, the clover came up thick and was an obvious benefit to the wheat crop."

Using the Reefinator to ameliorate and renovate the soil, Mr King said he "drops it in" to a depth of about 300 millimetres.

"We're obviously breaking through hardpans in the pasture paddocks and some of them will go into Devil wheat this year,'' he said.

"There's no other machine like this one that can break up and crush rocks and mix in the lime sand.

"It works a bit like a delver and with the mixing I know I'm getting the lime sand down faster to depth.

"That's a bonus while the soil is left in a more structured state that improves your moisture infiltration because you've also eliminated non-wetting.

"It's a bit like the old days using a one-way plough only you're not leaving the soil exposed to blow."

Mr King was so impressed with the performance of the 200 Series model, he bought an upgraded 300 Series model two years ago and is now "flat out contracting six months of the year".

"It's exciting to think we can bring what we used to consider as unproductive land back into a profitable enterprise," he said.

"It certainly adds value to your property and it's a more sustainable approach which I think will lead to more fertilise soils."

The Reefinator is designed with a working width of three metres and can dig up common laterite rock and crush it.

From the rear, the drawbar-mount Reefinator looks like a land roller, but it's when you take a look at the front of the machine that you gain a better understanding of how it works.

A total of 10 heavy duty ripping teeth are attached to wide individual flat shanks in box frames with the shanks designed with a cutting edge to promote the upwards movement of soil and rocks, cut into by the ripping teeth.

"It works like a cheese grater peeling off material," said Rocks Gone director and inventor Tim Pannell.

"Depending on the rock profile it generally takes about three passes to complete the job.

"The first pass scores and weakens the rock, the second pass scores and crushes and the third pass pulverises and levels."

Weight is a big part of the operation in conjunction with a working speed of about 10 kilometres an hour, which means an operator can complete a hectare an hour, employing three passes.

When the roller is filled with water the all-up weight for the machine is more than 21 tonnes.

"The rock roller also was specially built with deeper ribs to enhance resistance pressures to be able to crack and pulverise the rocks," Mr Pannell said.

He has also designed the ripping tynes to work at different depths to cater for various rock strengths.

Last year Rocks Gone released a H4 hydraulic Reefinator, which has more than piqued the interest of Mr King, who has placed it on his "wish list" for the future.

The H4 is fitted with four leading tynes and five at the rear with a new cable-suspended levelling blade that, in operation, levels the soil and crushed rock as you go.

The following ribbed drum (which weighs 30t when full of water) and the arms are the same design as the previous model.

The cable design was the preferred option to prevent undue stress on the hydraulic cylinders, while the tynes are hinged on cast steel housing with a 55mm pin.

"The shear pin in the 300 Series had to be designed to break but you could get up to 22.5t before it broke," Mr Pannell said.

"With the hydraulics you don't need the shear pin because it's live action process with give and take."

The hydraulic system features a 32 litre accumulator designed to handle up to 3000psi pressure but Mr Pannell said the working pressure range was generally between 1000-1500psi.

All rams and pivot points are on spherical mostly greasable bearings, specifically designed to be maintenance-free working so close to the ground.

Hoses plumbed off the cylinders are 25mm in diameter to accommodate high speed out of the cylinders on impacts.

"Pressure can ramp up quickly and with smaller hoses, oil can't escape fast enough from the cylinder," Mr Pannell said.