Projects to help get amelioration to the most out of soil

Many farmers are having success in ameliorating their soils and removing subsoil constraints that keep crops from achieving their true potential.

Research conducted with Grains Research and Development Corporation (GRDC) investment has found numerous examples of growers boosting their profitability by ameliorating soils to remove these constraints constraints, whether it be a hard pan, an acidic layer or water repellence.

However, Rowan Maddern, GRDC western manager of agronomy, soils and farming, says there is still much to learn, especially for farmers with variable soil types where there are multiple, complex constraints.

Dr Maddern said to help guide areas for future research investment, a national GRDC project will test business model options for emerging technologies that provide three-dimensional information about soils, and options that might allow growers to ameliorate variable soils 'on the go' without needing to stop and adjust machinery.

He said this would mark a slight shift in strategy away from investigating a single constraint at a time .

"Previous investments have largely focused on single constraints - such as acidity, compaction and soil water repellence, although the GRDC has more recently invested in a new series of projects that aim to address multiple constraints through improved soil management," Dr Maddern said.

He said there were a diverse range of issues throughout the country, according, naturally to soil type and climate.

"In the northern region these investments have largely focused on acid soils in southern NSW and soil sodicity, where soil swells when wet, causing issues in air and water movement through soil, and compaction in northern NSW and Queensland," he said.

"This existing research has provided key knowledge on soil constraints, which many growers have successfully applied on their farms, with good returns often achieved, particularly on more uniform soil types.

However he said in some cases, zero financial returns or even losses could occur following the soil renovation work.

For this reason he said it was important to know what to apply and where - for example, in the case of Western Australian growers who have inadvertently brought toxic clays to the soil surface via clay delving done to improve the structure of sandy top soils.

Dr Maddern said GRDC Grower Networks (previously known as GRDC Regional Cropping Solutions Network groups) had identified the need for methods, tools or technologies that would allow growers to confidently and cost-effectively remove soil constraints in paddocks with variable soils.

"An example would be a deep ripping machine that could follow variable depth compaction layers in a paddock and lift out in areas where no compaction is present or where ripping would damage the soil profile," he said.

The new GRDC project, to be led by consulting business Colere Group, will evaluate and report on existing and emerging technologies that provide three-dimensional data for multiple soil constraints within paddocks, and possible options for 'on-the-go' amelioration.

"Diagnosing and managing soil constraints in variable soils has traditionally been complex given interacting physical and chemical properties down the soil profile, and current approaches are expensive and labour intensive," Dr Maddern said.

He said he hoped ag-tech innovations could play a role in changing that.

"Advances in sensor technologies, data management and computer science are providing opportunities to diagnose soil constraints in real or near-real time within paddocks," he said.

"Combining this technology with soil engineering and crop science would overcome a significant barrier to the adoption of amelioration on variable soils."