Carbon sequestration describes the process of transferring carbon from the atmosphere to the terrestrial biosphere (soil or vegetation). Soils contain vast quantities of plant, animal and microbial residues in varying stages of decomposition and store more carbon globally than the atmospheric and living vegetation pools combined. However, there is still large uncertainty surrounding baseline soil C values and verifying the strength and permanence of carbon sequestered in different soil fractions. This project is focussed on assessing the quantity and quality of soil organic carbon (SOC) in agricultural soils as well as management and climatic effects on C sequestration. It will:
- establish a soil organic carbon baseline for Irish grassland and arable soils
- evaluate the rate of C sequestration in temperate pastures, according to climate, soil and agricultural management practices
- measure changes in bulk SOC content and labile/recalcitrant C pools in existing chrono-sequences of pastures
- determine the influence of environmental factors such as land-use change, soil type and management on the process of carbon sequestration and mineralisation.
Soil samples taken across a range of soil types as part of the Irish Soil Information System and SQUARE projects will be analysed. In addition, high frequency flux data from eddy covariance towers will provide information on carbon exchange at an ecosystem level and the impacts of management practices and climatic variability on C uptake.