Congratulations!Cierra Aldrich successfully presented her MSc thesis

7 November 2024

Photo: Cierra Aldrich Private

Cierra Aldrich successfully defended her thesis, titled "Combinations of Biochar and Rock Weathering in Tropical Soils for Enhanced Carbon Storage," under the supervision of Prof. Jens Hartmann and Dr. Maria-Elena Vorrath from the University of Hamburg.

The application of pyrogenic carbon (biochar) and enhanced rock weathering (ERW) in soils are regarded as prospective nature-based approaches to carbon sequestration and agricultural soil improvement. In the tropics, nutrient and hydrologically poor soils would benefit from biochar and rock material additions, while also providing optimal conditions for ERW. The co-deployment of such methods, particularly by co-pyrolysis of biomass and rock (PyMiCCS), is suggested in the literature to enhance carbon dioxide removal (CDR) and agricultural co-benefits. This study quantifies the carbon storage of different combinations of basanite rock powder and wood/straw biomass in an oxisol, using a 27-week incubation experiment that simulates elevated soil pCO2 and annual tropical rainfall. Preliminary results indicate that the addition of minerals to form PyMiCCS improves carbon conversion efficiencies and provides necessary plant nutrients to soils. However, biochar deployed alone has more than 2x the CDR potential per ton of material than PyMiCCS or co-deployed biochar.

Cierra's future plans include moving back to the US to work for an NGO or startup in biochar or enhanced rock weathering. We wish her all the best for her future.