Assessing the deployment of enhanced rock weathering methods for carbon capture in pastureland

Enhanced weathering (EW) refers to the acceleration of chemical rock weathering as a carbon dioxide removal (CDR) method for climate change mitigation. Long-term field studies are needed to develop methods to monitor, report and verify CDR rates before EW can be deployed on a large scale. However, t...

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Main Author: Seow, Sherryl Hui Shan
Other Authors: Patrick Martin
Format: Final Year Project
Language:English
Published: Nanyang Technological University 2024
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Online Access:https://hdl.handle.net/10356/174819
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-1748192024-04-15T15:31:48Z Assessing the deployment of enhanced rock weathering methods for carbon capture in pastureland Seow, Sherryl Hui Shan Patrick Martin Asian School of the Environment University of Waikato Terry Isson pmartin@ntu.edu.sg, terry.isson@waikato.ac.nz Agricultural Sciences Earth and Environmental Sciences Enhanced rock weathering Climate change mitigation Carbon dioxide removal Dunite weathering Enhanced weathering (EW) refers to the acceleration of chemical rock weathering as a carbon dioxide removal (CDR) method for climate change mitigation. Long-term field studies are needed to develop methods to monitor, report and verify CDR rates before EW can be deployed on a large scale. However, there are limited field trials globally and often only use basalt rock. Hence, our study aims to assess if CDR can be determined for another highly weatherable rock, dunite, through field trials across four pastureland sites in the Bay of Plenty, New Zealand. Dunite of two grain sizes was amended at rates of 40-100 t ha-1 across each site, and CDR rates were determined by the depletion of magnesium in the soil over time. Our initial sampling regime showed high variability in magnesium concentration measurements, which resulted in less accurate and precise CDR calculations. Therefore, we devised a second sampling regime to address spatial heterogeneity and natural variation in the soil. We sampled 20% more of the plot by volume, included replicates for statistical aggregation and homogenised the soil before collecting the samples. The improved sampling regime showed an average CDR of 1.47-12.77 t CO2 ha-1 y-1 across all application rates two years after the dunite amendment. Plots with fine-grained dunite had lower variability but no significant difference in CDR rate. We also observed added benefits to soil health as pH increased by 0.67±0.13 on average. However, nickel toxicity could be of concern at high dunite application rates and should be appropriately monitored and managed. Bachelor's degree 2024-04-12T04:07:52Z 2024-04-12T04:07:52Z 2024 Final Year Project (FYP) Seow, S. H. S. (2024). Assessing the deployment of enhanced rock weathering methods for carbon capture in pastureland. Final Year Project (FYP), Nanyang Technological University, Singapore. https://hdl.handle.net/10356/174819 https://hdl.handle.net/10356/174819 en application/pdf Nanyang Technological University
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Agricultural Sciences
Earth and Environmental Sciences
Enhanced rock weathering
Climate change mitigation
Carbon dioxide removal
Dunite weathering
spellingShingle Agricultural Sciences
Earth and Environmental Sciences
Enhanced rock weathering
Climate change mitigation
Carbon dioxide removal
Dunite weathering
Seow, Sherryl Hui Shan
Assessing the deployment of enhanced rock weathering methods for carbon capture in pastureland
description Enhanced weathering (EW) refers to the acceleration of chemical rock weathering as a carbon dioxide removal (CDR) method for climate change mitigation. Long-term field studies are needed to develop methods to monitor, report and verify CDR rates before EW can be deployed on a large scale. However, there are limited field trials globally and often only use basalt rock. Hence, our study aims to assess if CDR can be determined for another highly weatherable rock, dunite, through field trials across four pastureland sites in the Bay of Plenty, New Zealand. Dunite of two grain sizes was amended at rates of 40-100 t ha-1 across each site, and CDR rates were determined by the depletion of magnesium in the soil over time. Our initial sampling regime showed high variability in magnesium concentration measurements, which resulted in less accurate and precise CDR calculations. Therefore, we devised a second sampling regime to address spatial heterogeneity and natural variation in the soil. We sampled 20% more of the plot by volume, included replicates for statistical aggregation and homogenised the soil before collecting the samples. The improved sampling regime showed an average CDR of 1.47-12.77 t CO2 ha-1 y-1 across all application rates two years after the dunite amendment. Plots with fine-grained dunite had lower variability but no significant difference in CDR rate. We also observed added benefits to soil health as pH increased by 0.67±0.13 on average. However, nickel toxicity could be of concern at high dunite application rates and should be appropriately monitored and managed.
author2 Patrick Martin
author_facet Patrick Martin
Seow, Sherryl Hui Shan
format Final Year Project
author Seow, Sherryl Hui Shan
author_sort Seow, Sherryl Hui Shan
title Assessing the deployment of enhanced rock weathering methods for carbon capture in pastureland
title_short Assessing the deployment of enhanced rock weathering methods for carbon capture in pastureland
title_full Assessing the deployment of enhanced rock weathering methods for carbon capture in pastureland
title_fullStr Assessing the deployment of enhanced rock weathering methods for carbon capture in pastureland
title_full_unstemmed Assessing the deployment of enhanced rock weathering methods for carbon capture in pastureland
title_sort assessing the deployment of enhanced rock weathering methods for carbon capture in pastureland
publisher Nanyang Technological University
publishDate 2024
url https://hdl.handle.net/10356/174819
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