Sustainable Pathways to CN30 Milestone 7

The Carbon Storage Partnership (CSP) is a multi-party transdisciplinary consortium developing the knowledge and technologies required to underpin profitable, sustainable and socially acceptable pathways to a carbon-neutral livestock sector by 2030. This milestone reports progress on (1) a literature review, (2) semi-structured interviews with farmers, (3) long-term soil carbon measurements, (4) modelling of case study farms and (5) CSP communications and extension.

A literature review on the implications of grazing management for soil carbon, biodiversity, livestock production, profitability and ecosystem services has been completed. This showed that herbage mass was, on average, 42% lower under high compared with low grazing intensity treatments, but was 25% greater under systems that incorporated long spelling periods. Negative impacts of high grazing intensities were pronounced regardless of agroclimatic region, but were increasingly detrimental in regions with higher average annual rainfall. Herbage mass was 40% greater under high-intensity rotational grazing compared with continuous grazing; differences between rotational and seasonal grazing at lower grazing intensities were not significant. Outcomes of the review will partly inform the mitigation pathways to be modelled.
Semi-structured interviews with producers from across four NSW agroecological zones have been completed. Analysis of these interviews is underway. The intent here is to prepare a manuscript for publication in an international journal. Grazing management recommendations have been developed based on agroecological region (Temperate and Mediterranean, Southern Rangelands, and Northern Rangelands). Generally, in the higher rainfall Temperate and Mediterranean environment, farmer focus tends to be on managing grazing to optimise pasture and livestock providing while providing the enabling conditions to build soil C and other ecosystems services. In the rangelands, we found that grazing practitioners tend to be more conservative, managing landscapes with the primary aim of minimising degradation risk.

Measurements of soil carbon (building on long running field experiments) have been analysed and a further scientific publication is being prepared. There was a significant increase in soil C and N but minimal difference between individual treatments over 10 years due to underlying pasture establishment influence across the whole site. Our results demonstrated that continuous grazing (one paddock, no rest) had lower soil C than treatments with multiple paddocks (30) or longer spelling (120 days), although effects of stocking rate were negligible.

The CSP Communications and Extension plan and IP register have been updated. Extension engagements enumerate 138 events to date, of which 12,579 people have been directly engaged (interactive workshops, webinars etc), while indirect engagement through newspaper articles, radio interviews etc has been around 17.37 million, although there is the potential for multiple reaches for individuals.
Model initialisation using data collated from ten case study farms has begun. This includes biophysical, economic, greenhouse gas (GHG) emissions, natural capital and biodiversity assessments. People-centric meetings with farmers are continuing; as part of these, we are refining model parameters based on feedback such that model outputs most appropriately represent current farm systems. This step has been more time consuming than anticipated due to delays in refining model outputs based on farmer feedback. Preliminary GHG emissions and biodiversity assessments for two case study farms are presented, along with quantification of carbon in vegetation for all farms. These results are being refined at the time of writing and thus are subject to change.