A COMBINED WANTFA and University of WA long-term cropping trial will be extended by another three years.
It is major coup for WANTFA, given the site is only one of a handful of long-term trials left in Australia.
Although the project has secured funding until June 2016, a review by GRDC earlier prompted the recommendation of a number of changes.
WANTFA executive officer Dr David Minkey said the association aimed to maintain the trial for 12 years because a number of processes researched during the study took time.
"When we get to 12 years we will know some of the processes going on in the soil should slowly take hold," Dr Minkey said.
"Without that length of time you can't actually study those things properly.
"The results are just starting to come through now."
Dr Minkey said the next three years was key to providing significant information.
"We are ensuring that what we are doing in the no-tillage farming system ensures we are on track," he said.
"Particularly in the area of soil health and water use efficiency.
"We should be better informed after nine years as to whether we are heading in the right direction with a no-tillage farming system."
The trial, comprised of four main treatments, consisted of a range of different rotations, that included continuous cereal, diverse rotation of cereal, legume and brassica, continuous wheat, continuous pasture sown with a NDF disc seeder, and a cereal legume rotation sown with a knife point seeder for the first six years.
But it was soon evident all treatments, even the tine-seeded treatment had high residue levels.
"A knife point treatment on inter-row sewing and tramlines were showing similar responses to a zero-till machine on tramlines," Dr Minkey said.
"The zero-tillage machine and the no-tillage machine were neck and neck.
"In order to look at some different systems we have introduced burning and have some tillage.
"We use that to see how that effects things like organic carbon, disease profiles and so on."
The review by GRDC looked at all processes in the treatments.
"One of the comments was they acknowledged that this is a very important piece of research," Dr Minkey said.
The GRDC funded long-term no-tillage multidisciplinary trial will continue to study the benefits of high residue farming systems, minimal disturbance no-tillage systems on soil quality and will measure crop water use efficiency and yield.
But the WANTFA trial will now aim to further reduce crop residue levels for some treatments and will also include tillage.
As such WANTFA and the CSIRO will study soil water and nitrogen benefits from a fallow in a rotation to be contrasted to its possible negative effect of less soil carbon.
The treatment will be split, with half windrow burnt and the other half also tilled.
The expected low levels of crop residue cover and soil carbon would be used to study crop productivity and soil health.
