Composted chicken manure on cover cropped perennial pastures: WMG’s first Sandy Soils demonstration site
By Simon Kruger and Chanel Duggan, WMG
During the knowledge gathering phase of the Sustainable Solutions for Sandy Soils project earlier this year, growers and advisers across the region repeatedly raised organic amendments, composted manures among them, as an option they were interested in but had little local evidence for. WMG’s first demonstration site for the project is now in the ground at Gillingarra, looking at how a composted chicken manure application performs in an established perennial pasture on sandy country.
The site
The site is at Pine Break paddock, Gillingarra, hosted by Murray Grey and Colin Crane. It sits on light sandy soils with some small pockets of gravel, typical of the country across much of WMG’s project area. The paddock carries an established perennial pasture of Rhodes grass, Megamax panic and buffel grass, sown in August 2025. Prior to that it carried only volunteer annuals, and the paddock has no history of soil amelioration or fertiliser application in recent years.
Composted chicken manure was applied to approximately half the paddock in April 2026, with the other half left unamended as a control. A cover crop was sown across the full paddock on 23 May 2026, comprising wheat (50kg/ha), lupins (40kg/ha), triticale (20kg/ha), serradella pod (10kg/ha) and a clover mix of rose and arrowleaf (1.5kg/ha), sown with Seed Enhance (Fertitech) at 500ml/ha.
The demonstration design
The site is structured as a split paddock demonstration, with the 56ha paddock divided into two treatment zones of approximately 28ha each. Both zones have been divided into four monitoring quadrants of approximately 7ha, giving eight sampling zones in total. Sampling from all eight, rather than from a single location in each half, allows within-treatment variability to be observed and gives a more spatially representative picture of the paddock.
The design is unreplicated, reflecting the demonstration intent of the site and the practical constraints of a working farm. A single site over a single season gives a local indication rather than a result that transfers directly to other paddocks, and the data will be reported with that in mind.
The amendment
Composted chicken manure was applied to the amended half of the paddock at 38t/ha in April 2026. The material was sourced from a local chicken farm and composted in situ for approximately 12 months prior to spreading.
A sample of the composted material was submitted to APAL for full nutrient analysis, including trace elements. The headline macronutrients on an as received basis are set out below. Moisture content of the material at analysis was 16%, and the carbon to nitrogen ratio was 7.9 on an as received basis.
| Nutrient | Content (% w/w, as received) |
| Total nitrogen (N) | 3.56 |
| Phosphorus (P) | 1.22 |
| Potassium (K) | 3.40 |
| Sulphur (S) | 0.64 |
| Calcium (Ca) | 1.68 |
What is being measured
Monitoring across the site runs from establishment through to the end of the 2026 growing season. The program is designed to capture the production picture across both treatment zones through the year rather than at a single point in time.
A pre-treatment groundcover baseline was completed across the paddock in March 2026 using SLATS satellite groundcover measurement, prior to manure application. That gives a starting reference point against which in-season and end-of-season cover can be compared, with a second measurement planned for August 2026.
Dry matter cuts will be taken from each of the eight monitoring quadrants at three points through the season: early season in July, peak biomass in September, and post-graze in November. Cuts are taken to ground level and weighed fresh, with a subsample dried to calculate dry matter percentage and results reported as kg DM/ha.
At the peak biomass cut in September, pasture samples from each treatment zone will be submitted to Eurofins APAL for feed quality analysis covering crude protein, metabolisable energy and fibre fractions. Where practicable, perennial and cover crop species will be sampled separately.
Soil sampling across all eight quadrants was carried out by DPIRD on 16 June 2026, assessing pH, nutrition profile and soil compaction to 30 cm depth. That data provides the soil constraint baseline for the site. Visual observations of crop and pasture health, weed presence and groundcover condition will be recorded at each site visit, with photos taken throughout.
What comes next
Results from the July dry matter cut and the August groundcover measurement will be reported through WMG’s enewsletter and website as they become available. The full dataset, including all three dry matter cuts, the feed test and the groundcover monitoring, will be available in early 2027, alongside an assessment of the economics of the amendment.
Pine Break paddock is the first of WMG’s demonstration sites for the Sustainable Solutions for Sandy Soils project. Further sites across the WMG project area will be established and reported on as the project develops through 2026 and beyond.
Growers interested in finding out more about the project, or in discussing organic amendment options for their own sandy soil paddocks, are welcome to contact WMG at projects@wmgroup.org.au.
This demonstration site is part of the Sustainable Solutions for Sandy Soils project, funded through the Australian Government’s Future Drought Fund Resilient Landscapes Program with co-investment from the Government of Western Australia. The project is led by DPIRD in partnership with WMG, Mingenew-Irwin Group and Edith Cowan University. WMG thanks Colin Crane and Murray Grey for hosting the site and for their involvement in the project.
