Measuring Carbon Dioxide (CO2) Flux of Agricultural Practices in Sub-Saharan Africa

Agriculture has an important role in addressing two of the world’s most pressing problems: meeting global food demand and mitigating climate change. If agriculture is not practiced sustainably it will fail to meet future food demand and likely intensify the pace of global climate change. There are some agricultural practices, such as Conservation Agriculture, that can produce food sustainably and have the potential to mitigate climate change. However it is not clear which agricultural practices contribute to climate mitigation and by how much. By measuring the carbon dioxide (CO2) emissions of specific agricultural practices, the ability of practices to sequester or emit carbon can be quantified and used in climate mitigation policies. Since there is a lack of data showing the flux of CO2 for agricultural practices in developing countries, there is a great need to apply experimental methodologies to address this deficiency. Research was conducted using Bowen Ratio Energy Balance (BREB) instrumentation to quantify the energy balance and CO2 flux of agricultural practices in Lesotho and Zimbabwe. BREB micrometeorological systems were set up to compare and contrast tillage versus no-till practices and the effects of cover crops. The results demonstrated that with a vigilant approach, BREB micrometeorology provides real time measurements of CO2 flux that can measure and distinguish the differences between agricultural practices in southern Africa. The results generally confirmed that two of the major tenants of Conservation Agriculture i.e., reduced tillage (specifically no-till) and cover crops, sequester carbon more than tillage and fallow practices. Because the role of agriculture’s mitigation potential for climate change is not understood by the wider society, it is critical not only to communicate the results of this research but to raise awareness of the role of Agriculture in addressing two of the biggest problems that humankind will face in the future: feeding a burgeoning human population and preventing catastrophic climate change from record concentrations of atmospheric greenhouse gases. To that end, this thesis also touches on research investigating how to increase awareness and interest in agriculture by college students.