Inter-row sowing with stubble retained farming systems


Case study: Graham Mason, Ungarie, NSW – Inter-row sowing in a stubble retained farming system.

Property: “Westcourt” 8 km south west of Rankins Springs, 2500 ha.

Enterprises: Continuous cropping – wheat, vetch, canola, barley, lupins.

Soil type and pH: red soil with a pH of around 5.

 Overview:

Graham follows a continual cropping, no – till farming program. Some of his country is trending to acidic so he is currently liming those areas. He last limed ten years ago and has only just seen country slipping back.

Most of Graham’s cropping is done on a controlled traffic system and has been for nearly ten years, except some paddocks that have issues with contour banks and rocky areas.

Issues and observations of controlled traffic farming:

One issue with controlled traffic farming Graham has noticed is the occasional need for renovating his tram tracks which are currently becoming quite depressed. However he sees this as opportunity to use a green manure crop on these paddocks before cultivating, as well as the chance to use different chemical groups with pre-emergent prior to sowing the following crop.

Levelling of tracks is only done about every ten years.

One of Graham’s primary motivations for moving into controlled traffic farming was after converting to a disc seeder and finding a less than optimal performance towing behind a heavy tractor, or even in header tracks. So by using tram tracks his sowing efficiency with a disc seeder was greatly improved.

The ability to inter-row sow was also a key factor in his decision, allowing him to accurately sow with 2 cm spacings.

Issues and observations of inter-row sowing:

Graham sees a huge advantage in being able to accurately sow between stubble rows, sowing into clean ground and avoiding stubble contact, yet still retaining the stubble.

Smaller seeds such as canola germinate more evenly without stubble contact in the soil, as well as not being covered by stubble.

His system is still evolving and Graham feels it will keep evolving as things change. He has encountered herbicide resistance developing with rye grass and black oats and used a tyned implement as a control strategy. However it then created problems switching back to a disc implement – so he is certainly finding challenges and limitations within the system to overcome.

Another control strategy he uses for resistance is brown manuring vetch (varying his chemicals) which gives 100% control of weeds as well as supplying nitrogen and organic matter to his soils. He then follows the brown manure with canola which gives two years of good weed control.

As stubble from previous crops builds up in the rows Graham has found a disc seeder to be superior over a tyned implement in slicing through any old remaining crowns that may be present.

If a tyned implement must be used Graham may slash a paddock to aid in faster stubble breakdown.

Although he hasn’t physically recorded fuel usage differences between tram track and conventional Graham has noticed the engine of the spray rig working much harder if it deviates off the tram tracks.

His advice for anyone moving into a controlled traffic system is to make sure the tracks are suitable to header use as it’s this component which is an integral part of avoiding soil compaction.

Soil Health:

Benefits to soil health of controlled traffic farming Graham has observed is a far better retention of moisture in his soils, with soils being much more friable and softer.