CSIRO has partnered with the West Midlands Group (WMG) to study the long term benefits of different soil treatments on subsoil constraints and crop yield.
The trial is part of the GRDC funded, DAFWA administered Subsoil Constraints program, which is currently running across the Wheatbelt to examine the major soil constraints that limit crop production.
Soil amelioration practices are commonly used throughout the West Midlands region; deep ripping for sub-soil compaction, lime spreading for soil acidity, and spading to reduce water repellence and incorporate lime to combat sub-soil acidity.
WMG research agronomist Nathan Craig said this trial site combined all three soil amelioration practices, deep ripping, liming, and spading, and would be compared to an untreated control.
Mr Craig said normally trial sites were established for a number of years then abandoned when the project is completed. However, he said a 2013 trial site on Peter Negus’ property in Dandaragan was being re-utilised for the current project.
“This has the benefit of being able to look at the long term changes to the soil from the amelioration practices, and how this affects crop growth and yield,” he said.
Under CSIRO senior research scientist Dr Phil Ward’s direction, the site has soil moisture probes installed in the plots of interest to explore how these amelioration practices influence water use by the growing crop. Of particular interest is whether the crop has increased its use of water from the sub-soil as a result of the amelioration practices.
Also within this project, CSIRO senior experimental officer Dr Yvette Oliver will focus on using simulation models, such as Yield Prophet and APSIM, to give better predictions of the impact of subsoil constraints on grain yield.
Mr Craig said the key area of focus at the WMG site was determining the scale of yield penalty where the constraints of subsoil compaction and acidity are present, and incorporate this into the current models. By measuring yield and soil water uptake patterns over a number of years, the effect of seasonal conditions on soil amelioration practices can also be studied.
By conducting this research, CSIRO will be able to further fine tune Yield Prophet and APSIM for a larger range of soil types and conditions, and allow growers to estimate the long-term impacts of soil amelioration practices. Increasingly, grain growers are using the information from Yield Prophet to improve or adjust their management practices during the season.
WMG will work with CSIRO to manage the trial site to ensure the integrity of the data collected from the site.