College of Arts and Sciences Poster Presentations
Quantifying Pedogenic Carbon Content Within the Boise River Terraces Using Pressurized Calcimetry
Soil carbon is the third largest carbon pool within the global carbon cycle; however, soil carbon amounts are not well quantified, and exchange rates of soil carbon are not well understood. Soil carbon can be divided into organic carbon and inorganic carbon, where inorganic carbon (pedogenic carbonate) is precipitated during soil formation and accumulates over time in semi-arid and arid environments. Calcic soils within the semiarid regions of the Boise Valley result from active pedogenic accumulation of secondary CaCO3 resulting in prominent 'caliche' layers in soils formed on many of the Boise River terraces. The larger goals of this project are to quantify inorganic carbon sequestered within the Boise River terraces, and investigate rates of carbonate dissolution due to irrigation. This portion of the project focuses on developing methods for measuring inorganic carbon content in soils using pressurized calcimetry. Samples are acidified within a closed system to form CO2 under constant temperature, allowing time-pressure readings to delineate the levels of inorganic carbon present. Future work will reveal trends in carbon content with depth in individual soil profiles, and variations in carbon content for terraces of different ages.