Benefits of retaining stubble

Buzz words such as “No Till”, “Direct Drill” and “Minimum Till” have been used for many years to describe methods of planting in broad acre situations.  However, farmers and machinery manufacturers alike have found it easier to get rid of stubble, burning it instead of developing stubble handling techniques.

• Retaining stubble slows down wind speed at ground level thus shielding the soil and giving it some structure to protect it against the wind.

• Retaining stubble stops run-off, it ensures that rain will be absorbed into the soil where it falls and not erode yet more soil traveling to some dam catchment.

• Retaining stubble protects the soil from the sun rays thus allowing micro activity beneath the surface and reducing evaporation due to heating of the soil.

• Retaining stubble ensures that organic material is returned to our soils thus promoting micro activity and a better soil structure.

Stubble retention is desirable as an overall management tool in sustainable broad acre farming.

The biggest impediment to stubble retention has been the inability of machines to plant a crop and leave the stubble on top.  The vast majority of planting machines are tined machines and in trash they simply drag the stubble along and clog up.  In lighter stubble, the machines that do get through incorporate the stubble and can tie up nutrients in the soil.

Increase productivity

We have taken on the challenge to overcome the traditional problems associated with disc planters and we believe the development of our Bullet disc planter heralds a new era in planting technology because our machine can retain the stubble but it can do much, much more;

• We can plant at speeds up to 25kph or the same speed as the farmer is now spraying depending on conditions.

• We use 35-55% of the fuel used planting with a tined machine.
• Most of all, we can plant in a fraction of the time it takes tined implements and other disc seeders thus giving the farmer flexibility to take advantage of rainfall patterns and planting windows.

The Bullet has been developed in New South Wales over the past seven years and is now operating across the wheat belt with machines operating in NSW, Vic, SA and WA.

Reduced compaction around seed zone.

The Bullet disc openers operate at an angle to the direction of travel and the vertical.  Many disc machines operate utilizing only an angle to the direction of travel.  When using this angle only, the trench is opened utilizing compressive forces, i.e. the soil is compressed until it bulges upwards and forms a trench.

When the disc operates at a combined angle, i.e., angled to the vertical as well as the direction of travel, less compressive forces are required to separate the soil to form a trench as the disc obtains undercut and partially lifts the soil utilizing tensile forces.

This is important as it is well known that compressed soils have many drawbacks such as lower water infiltration and reduced microbial activity.  This is even more relevant as the row of soil we are dealing with will end covering the seed and unhealthy soil in this area can slow down growth in certain soils.

It also reduces draft requirements which can be considerable when planting at depth.