Plant responses to simulated carbon capture and storage (CCS) CO2 pipeline leakage: the effect of soil type

Abstract

Carbon capture and storage (CCS) has been proposed as a bridging technology to enable the transition to an energy system based on renewable sources. Many high CO2‐emitting industries (such as the power industry) are distant from potential carbon storage sites (such as offshore geological reservoirs) and an infrastructure of CO2 transportation must therefore be developed to carry the CO2 to safe storage. As such there is a need to understand the risks involved and the mitigation of potential leaks associated with CCS and dense‐phase CO2 transportation networks. Since 2012 a number of experimental studies have provided a mechanistic understanding of the risks posed to crops as a function of CO2 leakage from CCS infrastructure. However, what remains largely unresolved is the role played by both soil type and soil structure in mitigating and / or enhancing plant stresses. In this study we provide an experimental framework to evaluate these effects. Wheat and beetroot were grown in four different experimental soils to test the effects of specific soil attributes (organic, low pH; organic, open structure; organic, limed; loam, neutral pH) on crop performance when exposed to high levels (∼40%) of CO2 in the soil environment. Comparison between treatment and controls and across the soil types reveals little difference in terms of biomass or plant stress chemistry. From a stakeholder perspective these findings suggest that soil type may play only a minor role in mitigating or amplifying plant stress in response to the unlikely event of a CO2 leak from CCS infrastructure.