A specially-designed Ausplow DBS precision planter being used in New South Wales. The DBS is a Clayton's version of deep ripping and a defacto Keyline system, encouraging rain to stay where it falls.

A specially-designed Ausplow DBS precision planter being used in New South Wales. The DBS is a Clayton's version of deep ripping and a defacto Keyline system, encouraging rain to stay where it falls.

(PART TWO OF A THREE PART SERIES)
By JOHN RYAN AM
I often wonder what my uncle Percival Yeomans (PA), an engineer and farmer in New South Wales, would say about modern day crop establishment practices.
He was, of course, the inventor of the Keyline contour system which basically was designed to retain moisture where it fell, eliminating washaways and water erosion on slopes and reducing water-logging in the valleys.
It came after he had been experimenting with various tillage techniques for pasture establishment and regeneration in the early 1950s.
Initial attempts started with a chisel plough designed by Texan farmer Graham Hoeme and named after him.
But Percival soon found the two inch wide shanks tore a lot of roots out of the soil while requiring a lot of horsepower to pull it.
Further investigation led him to develop his own plough, called the Yeomans plough, which was used for keyline plowing when he established ‘The Keyline Plan’ in 1954.
It was essentially designed, with thinner shanks, to lift and aerate the soil while limiting soil disturbance to minimize oxidation of organic matter.
For many years the Yeomans plough became the tillage tool for deep tilling and pasture renovation but the lack of high horsepower tractors limited its ability to work deep in the subsoil.
Further development was based on work in Texas with a ‘Lubbock Vibrating Plow’ which was designed with a vibration mechanism, driven off the tractor PTO.
It featured a dual eccentric counter-balanced rotor system which acted as a unbalanced flywheel.
As the flywheel turned, it caused the entire implement to vibrate and the machine was made out of angle iron and bolted together rather than welded to withstand the vibrations.
Its most important feature was that it broke up hardpans, yet left the soil relatively undisturbed.
In the early 1970s I began developing a similar machine which was later called the Shakeaerator, which was in commercial production between 1974 and 1979 and was manufactured under licence in England.
It was able to penetrate deeper into the subsoil and used less horsepower than the chisel plough which was restricted by a spring-loaded tine and a C-shank, which increased horsepower requirements.
The Shakeaerator worked better in dry, hard soils which resulted in good fracturing but very high wearing parts.
It led to farmers reverting to the chisel plough again with a lot of work often done after rainfall events.
This led to soil collapsing, causing re-compaction and losing soil aggregation or structure which plant roots couldn’t penetrate to obtain deeper moisture and nutrients.
It was found that ripping into established pasture, or after seeding with roots established, maintained soil aggregation, allowing good infiltration of moisture and easier access for plant roots to grow deeper in the subsoil.
My experience was that ripping at seeding allowed plants to develop roots quicker which reduced soil collapsing to maintain good infiltration of moisture and air.
It was the right idea but it proved difficult to obtain accurate seed placement as seed often fell into the deeper furrow created by the digging blades.
That’s when I started to develop the DBS no-till system, which in effect, is a Clayton’s version of deep tilling – loosening the soil, aerating it, providing moisture infiltration and achieving accurate seed placement.
It also is a defacto Keyline system encouraging rain to stay where it falls – how many DBS owners have trouble filling their dams?
So now we’ve arrived at our next development. We’ll continue the story in our September edition of Ausfacts.

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Publish Date: 
Saturday, June 6, 2020