P.PSH.2134-NEXUS Involve & Partner: impacts of biochar supplementation on productivity, profitability and GHG emissions
At the conclusion of the biochar trial, the average liveweight of biochar cohort was 5% heavier than unsupplemented control animals.
| Project start date: | 15 September 2021 |
| Project end date: | 30 September 2024 |
| Publication date: | 22 April 2024 |
| Project status: | Completed |
| Livestock species: | Grass-fed Cattle |
| Relevant regions: | National |
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Summary
This Involve & Partner project is linked to the University of Tasmania NEXUS project and in collaboration with a commercial beef producer (TasAgCo), modelled and measured the impact of a biochar feeding regime on whole farm productivity, profitability and GHG emissions.
Objectives
1. Collaborated with one Involve and Partner Farm to pilot initial NEXUS adaptations or greenhouse gas mitigations or emergent Livestock Productivity Partnership project(s) recommendations. The adaptation trialled on farm will be Biochar.
2. Measured the impact of biochar supplementation on the growth rate of ~200 calves over 15 months and evaluated, through a benefit cost analysis, the impact on whole farm and profitability. This will include the identification of the price point required to make biochar supplementation a profitable intervention for producers.
3. Modelled the impact of biochar supplementation on whole farm GHG emissions and soil organic carbon.
4. Engaged 20 additional producers and 10 service providers across a series of workshops to support learning around Involve and Partner activity and working through the practicalities of implementing further NEXUS outcomes in the farm context.
5. Monitored the wider impact of Involve and Partner activity by conducting a benchmarking case study of the IPF that will provide biophysical, economic and social data to measure practice change over time.
6. Monitored the impact of workshop involvement by surveying attendees*. This will be in alignment with MLA’s monitoring and evaluation strategy for KASA (knowledge, attitudes, skills and aspirations).
Key findings
• At the conclusion of the trial, the average liveweight of biochar cohort was 5% heavier than unsupplemented control animals.
• No significant effects of biochar supplementation on manure organic carbon were measured, although this could be due to relatively low numbers of manure samples taken.
• An economic analysis of the biochar-fed animals determined a net profit of approx. $80 above that of the control animals, although based on a higher than average meat price at $4.50/kg LW for premium Wagyu-cross meat, biochar costing $0.10/head/day, equivalent to ~ $2,500/t biochar, without also including any additional costs associated with labour and capital purchase of feeding troughs.
• The cost-benefit-mitigation analysis showed that liveweight gain would need to be greater than 10% for biochar feed supplementation to be cost-effective, assuming carbon prices of $25–$75 per tonne of carbon dioxide equivalents (CO2e), biochar cost of $2,000 per tonne of dry matter (DM) and liveweight valued at $2.75/kg.
Benefits to industry
The field experiment illuminated several issues associated with feeding biochar in the form we used (loose powder). Workshops on farms who had used biochar as a feed supplement for 5-10 years, illustrating other forms of feed delivery, e.g. mixing powdered biochar in silage, may be more amenable to livestock consumption. We showed that incorporation of salt, while ensuring that biochar remained dry, were amenable to greater intake. Workshop attendees discussed wider benefits associated with their experience with biochar, including lower proportions of dark coloured meat, reduced sheep fly strike, reduced mastitis and lower incidence of parasites. Several barriers associated with adoption were raised, too, such as feeding mechanisms in extensive grazing systems, scalability, cost, suboptimal cost-benefit ratios and regulatory burden. Time commitment required by practitioners – and associated opportunity cost - was a foremost priority when deciding whether or not biochar should be adopted. Despite such barriers, our work suggested that peak adoption ranged from 10-69% depending on perceived environmental benefit, while time to reach peak adoption was relatively expeditious due to the reversibility and trialability associated with feed supplementation.
MLA action
Many prospective opportunities worthy of deeper investigation were uncovered. In particular, industry engaged recommend further research on:
(1) Effects of biochar feedstocks (e.g. wood, crop residues etc), as peer-reviewed literature indicates a large disparity in liveweight gains associated with differing feedstocks.
(2) Impacts of long-term feed supplementation (at least three years) on:
- liveweight gains
- cost-benefit ratios
- soil organic carbon stocks (including mineralisation, micro aggregation, occlusion, rhizodeposition and sequestration; viz. Weng et al. 2022)
- meat and milk quality, including dark cutting meat and microbial content of milk
- enteric methane mitigation and net emissions intensity, which hitherto have been largely unexplored.
Future research
We underline many prospective opportunities worthy of deeper investigation. In particular, we recommend further research on (1) effects of biochar feedstocks (e.g. wood, crop residues etc), and (2) impacts of long-term feed supplementation (at least three years) on liveweight gains, soil organic carbon stocks (mineralisation, rhizodeposition, micro aggregation, occlusion and sequestration), meat and milk quality, enteric methane mitigation and net emissions intensity. Our results imply that biochar feed supplementation improves environmental sustainability and animal welfare, although further research is necessary to dissect this notion.
More information
| Project manager: | Andrew Morelli |
| Contact email: | reports@mla.com.au |
