Soil study promises to double crop yields

The New Horizons project will study the benefits of improving the top 50 centimetres of the soil profile to increase water holding capacity, nutrient retention and ultimately boost yields.

The project was launched by SA Agriculture Minister Gail Gago, who opened the first trial site six kilometres north of Karoonda.

"Until now, research has focused on working to improve the top 10cm of soil where most roots grow and standard agricultural equipment can reach, but there is growing evidence that productivity can be increased by using the sub-soil," she said.

"This project aims to look at deeper subsoil structures and to look at a range of different ways of improving the quality of the soil so we can improve productivity."

The government has committed $850,000 for the project's first year, with two more trial sites to be established at Cadgee in the South East and on the Eyre Peninsula.

"As soon as we started talking about it, I could just see that this had the potential to be the next revolutionary step in dryland farming," Ms Gago said.

"We know that the modelling and research shows us the sorts of productivity improvements that can be gained from this sort of research could produce economic benefits of around $1 billion a year. That's not a bad bang for our buck - $850,000 for $1b improvement a year."

Mallee Sustainable Farming chairman Ian Hastings said a project of this nature was very important for Mallee farmers.

"There was a study done recently which said that over the past 20 years the cost of inputs for Mallee farming has gone up by 40pc in real terms and our returns have stayed the same in real terms," Mr Hastings said.

"We really are being pushed into a corner and we desperately need things like this to help us lift our productivity.

"Forty or 50pc of our Mallee area is lighter sands and if we can lift the productivity of those areas it is going to make a huge difference to us."

Rural Solutions intern Tania Moreno with PIRSA group executive director Andrew Johnson and project manager Paul Dalby.

Click on the image above to view more photos from the launch.

Project director Paul Dalby is confident of achieving massive yield gains for farmers across the state.

"We know that about 50pc of SA's cropping lands are amenable to this sort of intervention," Mr Dalby said.

"They're either infertile sand or they're very sodic clay soils, very compacted soils.

"We think we should be able to at least double yields, and that could be through adding clay, adding nutrition, even adding organic matter at depth to try and get a soil profile of 40 to 50cm which is high in organic matter and nutrients so the roots grow down deep where there's extra moisture.

"Our intention is to firstly demonstrate that we can double yields on this site. Our second objective is that we want to understand what causes that doubling of yield so that we can provide advice to farmers on how they can achieve that consistently.

"We're going to put in everything we can, we're going to throw the kitchen sink at the soil. We're going to put in clay, organic matter, nutrients and maybe gypsum and try and double the yield. Then we're going to take things out one by one to see what it is that delivered the benefits - was it the nutrients, was it the soil structure, was it the clay holding water?"

Mr Dalby knows there is a lot of work to be done before farmers adopt new techniques.

"The cost of doing that soil modification, of dragging a ripper through, is very high, so farmers are only going to do it if they know they are going to get a positive effect - at the moment they don't know," he said.

* Full report in Stock Journal, January 30, 2014 issue.