Soil Carbon Additions In Pima County To Address Local Climate Change Resiliency

Abstract

Current atmospheric carbon dioxide (CO2) concentrations are soaring above 400 parts per million, leaving our growing human population desperately searching for solutions to avoid catastrophic impacts climate change. Policies are being implemented in order to help slow this change, but the answer of “how” has yet to be agreed upon. Pima County is currently exploring this “how” under terms of their 2018 Sustainable Action Plan to reduce its carbon emissions by 50% by 2025. Pima County aims to implement climate adaptation measures in its operations to support climate change preparedness and resiliency within five areas of focus: carbon (C), water, landscapes, materials, and workforce. Soil carbon addition can serve as a possible biogeochemical solution for capturing and sequestering C at a large scale; however, the specific types, application rates, and land use strategies of these C amendments have yet to be explored locally or quantified within Pima County. Compiling this information for three different carbon amendments— biochar, mulch, and compost— is critical in order to make soil a viable solution for addressing County climate goals. Our research seeks to quantify current County sites with and without carbon amendment practices to assess baseline soil C concentrations and the effectiveness of management practices in Pima County across croplands, rangelands, barren degraded lands, and urban landscapes. Data were compiled from the existing scientific literature and on-the-ground measurements. This work will address the specific landscape goal of the Sustainable Action Plan to maintain or expand the number of County sites with composting and soil carbon amendment practices. Ultimately, the literary analysis and experimental results will become a critical component in achieving Pima County’s goal of 50% reduction in carbon footprint by 2025.