Agroforestry is vital for achieving net-zero emissions from agriculture. In partnership with an offsetting standard, this PhD seeks to establish the carbon sequestration benefits of agroforestry systems through quantitative means.
Two of the most promising opportunities to achieve net-zero greenhouse gas (GHG) emissions from agriculture are soil organic carbon (SOC) sequestration and agroforestry. Agroforestry is widespread in developing countries and is being increasingly considered in other regions. It covers a wide range of systems including intercropping, silvopasture wood lots, orchards, wind breaks, and home gardens. As well as the benefits of “locking-up” atmospheric carbon in woody biomass, agroforestry systems provide significant benefits to their soil. The importance of this has been highlighted by the recent 4-per-1000 initiative, which has renewed interest in the potential of SOC to both reduce net GHG emissions and to improve food security. Whilst the benefits of agroforestry systems to soil carbon storage and functioning have been identified, they have yet to be quantified sufficiently well to promote adoption at the scale required to contribute significantly to a low carbon future.
What is the potential for soil carbon sequestration in agroforestry systems?
For important specific production systems (such as silvopasture, intercropping), what are the cost-benefits of adoption, and what should the corresponding carbon price be to enable adoption?
How viable are low cost monitoring methods (such as remote sensing) to assess soil carbon sequestration, and other potential ecosystem services provided by agroforestry systems?
This studentship will be conducted as a CASE partnership with the Plan Vivo Foundation (www.planvivo.org). The programme will consist of the following activities
A quantitative review of the potential carbon sequestration and other ecosystem services provided by agroforestry systems. This will build on the reviews of Feliciano et al. (2017) and Torralba et al. (2016), supplemented by case studies from Plan Vivo projects.
Development of the SHAMBA modelling system (https://shambatool.wordpress.com/outputs/
) ready for inclusion in the Cool Farm Tool (https://coolfarmtool.org).
Validation of the resulting tool on case studies at Plan Vivo projects in developing countries
Building on other PhD projects supervised by Ryan, test the capacity to combine the model with low cost monitoring programmes to provide robust estimates of soil carbon sequestration.
A comprehensive training programme will be provided covering generic transferable and professional skills. Training will be provided in quantitative meta-analysis, mixed-effects modelling, and process-based soil carbon modelling through direct supervision and courses at the University of Edinburgh. Training can also be provided on remote sensing of the landscapes. With Plan Vivo and case study project staff, you will also learn about how carbon offsetting project in the tropics work, and the role of agroforestry in rural livelihoods.
Feliciano, D, Ledo, A, Hillier, J & Nayak, DR 2018, 'Which agroforestry options give the greatest soil and above ground carbon benefits in different world regions?', Agriculture, Ecosystems & Environment, vol. 254, pp. 117-129. https://doi.org/10.1016/j.agee.2017.11.032
Soussana, J.-F. et al. 2018. Matching policy and science: rationale for the ‘4 per 1000 soils for food security and climate initiative. Soil & Tillage Research (online). doi: 10.1016/j.still.2017.12.002.
Torralba M et al (2016) Do European agroforestry systems enhance biodiversity and ecosystem services? A meta-analysis. Agriculture, Ecosystems and Environment 230: 150–161