DPIRD team up with collaborators to unlock the long-term profitability of soil amelioration practices
Project name
Prolonging profitability and longevity following soil amelioration
Grains Research and Development Corporation (GRDC) Update Papers, 26 Feb 2024
Project code
DAW1901-006RTX
Addressing soil constraints
The Department of Primary Industries and Regional Development (DPIRD) Principal Research Scientist, Dr Stephen Davies, co-authored a research paper alongside Peter Newman, Rob Sands, Ben Curtis, Kelly Ryan and Hilary Bunny, with the findings presented at the 2024 the Grains Research and Development Corporation (GRDC) Research Updates.
This research highlighted GRDC-supported soil amelioration work in Western Australia (WA) reporting increases in productivity over the past 15 years.
The study focused on the main soil constraints of water repellence, soil acidity at depth (20–50cm) and soil compaction at depth (20–60cm).
Leading growers in WA have adopted the “lime, flip, and rip” approach with great success.
Lime, often sourced as coastal limesand or alternative on-farm lime, is applied to reduce soil acidity.
Soil inversion, using tools like rotary spaders, mouldboard ploughs, or modified discs, mixes the soil to improve water infiltration and incorporate lime.
Over the past 15 years, growers have adopted deep rippers that can rip to 500mm or deeper to correct compaction created by the ever-increasing weight of modern farm machinery.
Current research has shown increased production, however its impact on overall farm profitability has been less clear.
Research method
Researchers identified growers with long-term records of soil amelioration and compared their data to that of farmers in similar rainfall regions who did not use these practices.
All data was presented on a per-hectare basis, and all data different regions was combined to provide an overall view of the financial impact of soil amelioration.
The key financial metrics compared between businesses included:
- Estimated plant available water.
- Average crop yields of major crops (wheat, barley, canola)
- Water use efficiency
- Operating profit
- Operating profit per millimetre of effective rainfall
- Total operating costs per hectare
- Total machinery value per hectare
- Total plant ownership, maintenance, and labour (TPML) costs
- Return on assets managed (ROAM).
Profitability
The average farm size and crop area for WA farms in 2022 were used to demonstrate whole farm profitability.
The scale of farms differed between the amelioration group and the standard group, with the former generally being larger.
Despite receiving less rainfall on average, the amelioration group had higher crop yields and used water more efficiently.
Over 10 years, the amelioration group had an annual operating profit of $292 per hectare compared to $192 per hectare for the standard group.
This difference in profit resulted in an average increase of $3.76 million in extra profit over 10 years for an average crop area of 3765 hectares.
Operating costs were $59 per hectare higher for the amelioration group, partly due to the costs associated with higher yields.
Machinery investment was similar between the two groups, with total machinery value increasing significantly over 10 years.
Total plant ownership, maintenance, and labour costs were slightly lower for the amelioration group as a percentage of income.
The amelioration group had a higher return on assets managed (ROAM), indicating better overall financial performance.
Immediate yield and soil benefits
Farmers who used soil improvement methods like adding lime, mixing, or inverting the soil, and deep ripping achieved higher yields and profits, even with less rainfall.
While skilled farming practices also contributed, soil amelioration played a significant role.
Current soil amelioration methods first started being adopted by growers around 2009, and many farmers saw immediate benefits.
The last 3-years of the study showed the highest profits and yields, indicating ongoing improvements.
Dr Stephen Davies said the study confirms soil amelioration practices are profitable when conducted correctly and soil constraints are well understood.
Funding partners / project collaborators
Grains Research and Development Corporation (GRDC)
Planfarm
Farmanco
More information
Click here to read the GRDC webpage Soil amelioration increases profit by $100/ha per year over 10 years
Contact
Dr Stephen Davies
DPIRD Senior Principal Research Scientist
E: Stephen.Davies@dpird.wa.gov.au
P: (08) 9956 8515