Illustration 1: Once soil structure is in place, the environment created by the DBS becomes a virtual bucket, capable of holding moisture, whether that be from rain, water vapour (relative humidity in the soil) or from liquid fertilisers. The illustration also shows how sowing near-row doesn’t disturb existing stubble and old roots.

Illustration 1: Once soil structure is in place, the environment created by the DBS becomes a virtual bucket, capable of holding moisture, whether that be from rain, water vapour (relative humidity in the soil) or from liquid fertilisers. The illustration also shows how sowing near-row doesn’t disturb existing stubble and old roots.

Illustration 2: Ausplow recommends using coulters on its precision seeders to remove any stubble which may affect seed germination.

Illustration 2: Ausplow recommends using coulters on its precision seeders to remove any stubble which may affect seed germination.

By JOHN RYAN AM
It has been more than 30 years since I designed the DBS precision seeder.
My aim was to improve better crop establishment
while improving soil health.
And while we have seen many technological advances over the past three decades, I really haven’t made many changes to my original design.
What was achieved with the first DBS remains the same today.
It started with a narrow digging blade having a reverse digging angle which required more pulling power.
This was done intentionally to create a bursting action of soil particles, with space for roots to grow into and to hold air and water, therefore creating an environment for healthy root growth.
Precision seed depth was achieved by parallelogram linkage, embracing the tine and covering wheel.
It was called a ‘press wheel’ in the early 1990s but I believe ‘covering’ is a more appropriate term because it follows a closing tool, which forms a firm base to place seed onto.
The rolling action of the covering wheel causes soil fines to cover seed, while forming a water-harvesting furrow.
The covering wheel has a light ground pressure so as not to compact soil and not close air and water voids.
The soil fines covering the seed are made by the closing tool shaking soil particles from plant roots (stubble and even weeds), and these fines become the building blocks of soil structure as they move during the plant’s growth.
They associate with root hairs and organic material as complex biological processes create microscopic fungi, eventually leading to what we know as organic carbon.
Once this soil structure is in place, the environment created by the DBS becomes a virtual bucket, capable of holding moisture (Illustration 1), whether that be from rain, water vapour (relative humidity in the soil) or from liquid fertilisers.
The minimum tillage effect of the knife blade retains all plant roots in the soil.
I would recommend using coulters (Illustration 2) on our precision seeders to further enhance this process to remove any stubble which may affect seed germination.
Roots being left in the soil to decay provide pathways for water run-off and air to enter creating an environment for microbes to colonise.
This is the crux of our BioFurrow™ hypothesis.
The non-cultivated inter-row remains firm and dry reducing weed growth, giving good trafficability, while water run-off means that the furrow receives an accumulation of water essential in dry years with low rainfall events – even from heavy dews.

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Publish Date: 
Thursday, March 31, 2022