Changing farming practice at Marrar

Through on-farm trials he is finding how stubble height correlates with fallow efficiency, as well as the flow-on effects for the following crop.

The advent of no-till farming practice was innovative 30 years ago, but Mr Fox said recent work he has done has taken that concept to a new level.

"We want to continually improve the soil structure," he said.

"And while no-till was very important at the time, we are now looking to preserve as much ground cover through our cropping rotations as possible."

The use of disc seeders, which allows the planting of crops through the previous year's stubble, has been instrumental in Mr Fox achieving his aim.

"We have learned a lot about the improvement in soil structure and the benefits of having a healthy soil," he said.

A trial conducted in 2015 determining the value of taller stubble residue through a favourable winter but with a 'bob-tail' spring showed stubble 30 centimetres high was preferable to stubble 15cm high.

"We found there was a direct correlation between the stubble height and crop yield," Mr Fox said.

"The crop of barley yielded half a tonne better with the 30cm stubble and it was an indication to us that stubble height had a really big impact of fallow efficiency."

In his dryland cropping enterprise, Mr Fox said capturing and retaining soil moisture in the fallow was critical for the success of the following crop.

"It is all about minimising water evaporation," he said.

"In 2015 we made the decision that stubble height was really important and the best way to maximise that height was with a stripper front.

"And the only way we can retain stripper stubble and sow through it is with discs, eliminating blockages and yet improving soil structure futher."

Understanding the fragility of his soil through his work in improving soil structure and thus increasing the capacity to retain moisture, Mr Fox said the next step was to fathom the loss of organic carbon through the past 150 years.

"Soil carbon is the basis of the buffering capacity in our soils and enables the ability to store water, nutrients and heavy metals," he said.

"There has been a gradual decline in our soils, which has highlighted issues such as the toxicity of available aluminium.

"The high concentration of aluminium here is impacting on our soil causing hardpans at 150 and 500 millimetres as it drops the fine silt from our soil which accumulates at those levels.

"They are challenges we are now working through."

Mr Fox said the rise of aluminium in the soil on the family farm is a consequence of past practices, which at the time, were seen as groundbreaking in terms of lifting farm productivity.

He pointed to the growth of clover dominant pastures and use of MAP and DAP fertilisers as being some of the major contributors to the decline in soil organic matter.

"At the time their use was widespread and acceptable," he said.

"But we now recognise that the natural capital was being 'mined' and transferred to cash in the bank without any payback to the land."

The loss of organic carbon has created these chemical hard pans, and they in turn are restricting root development and ultimately crop yield.

"We have to break through these hardpans and improving soil structure so plants can have access to the available soil moisture and nutrition, and especially as the seasons turn dry."