Trial Overview:
In the 2025 summer cropping season, a sorghum crop on the Darling Downs (total area 299.1 ha) was seeded in mid-September and harvested in mid-February. The trial compared Worm Brew - Worms Downunder's liquid worm cast concentrate, a microbial product - against a standard liquid phosphorus fertiliser. The trial was run to determine if trends or differences in yield outcome could be observed where Worm Brew was applied at planting compared to the standardised application of liquid phosphorus at planting.
All liquids were applied as a liquid injection at planting. A single 26.8 ha section received Worm Brew at 20 L/ha plus 5 L/ha of bio stimulant (a food source for microbial populations), while the remaining 272.3 ha received the standard industry liquid phosphorus fertiliser at ~16.6 L/ha. Both treatments were applied through the same liquid injection system on the planter.
The total application cost for the Worm Brew treatment remained $1.50 per litre (combined Worm Brew + bio stimulant), as did the phosphorus liquid fertiliser.
Yield data was extracted directly from the harvester’s header yield maps and averaged across each treatment area.
Results:
- Worm Brew treatment (26.8 ha): average yield 4.9 t/ha (as reported from header yield maps)
- Standard phosphorus treatment (272.3 ha): average yield 4.5 t/ha
Yield advantage: +0.4 t/ha (or +8.9 %) in favour of Worm Brew treatment under identical growing conditions, soil type and management.
Economic Analysis (based o n combined Worm Brew +activator costing $1.50/L total and sorghum at ~$300/tonne at time of trial)
Key takeaway:
The Worm Brew treatment area delivered, on average, an extra 400 kg of grain per hectare. After accounting for the application rate and bio stimulant inclusion, this still returned an additional $107.40 net profit per hectare compared with the standard phosphorus program - representing a strong return on the incremental investment.
This demonstration shows that Worm Brew, when liquid-injected at planting together with a bio stimulant, can improve sorghum yield and profitability. While further replicated trials are required, this header data provides strong practical evidence that Worm Brew is a viable, higher-performing
alternative (or complement) to traditional liquid phosphorus fertilisers in sorghum.
The yields presented are the direct averages from the harvester header data maps (rounded to 1 decimal place as displayed). More precise calculations (4.869 vs 4.539 t/ha) show a similar pattern with a +0.33t/ha advantage, confirming the practical benefit observed.
