On-farm carbon capture and storage capacity within different dairy production systems: A system dynamics approach

Following the initial base project to determine the economic and environmental impact of dairy production in South Africa, this project will focus on the total estimating effect of carbon capturing and storage capacity within on-farm dairy production systems.  Where the previous project measured carbon emissions, it is possible, depending on the dairy system, might be a carbon neutral or even a carbon sink and not a carbon source as such. However, to know, one needs to measure.

Such a complex system to estimate carbon sequestration and the role of cows as biogenic sources of carbon, will include many variables and needs to be included in this model. Carbon in natural cycles will be different from carbon in fossil fuels since it includes the natural carbon and nitrogen cycles. Processes like photosynthesis from trees and plants when carbon is taken from the atmosphere are followed by the the sequestration of carbons through the leaves and roots by converting carbon to cellulose to build the plant while oxygen gets released back into the atmosphere and when plants get decomposed, carbon gets captured by soil. Herbivores, including dairy cows, can use these plants which is inedible to humans and convert it into valuable nutrient-dense foods for humans. However, this rumination process where microorganisms break down these complex plant nutrients cause the release of methane (CH4) in the atmosphere where methane gets converted back through the process of hydroxyl oxidation to carbon dioxide, which can be taken in by plants; hence a full completion of the cycle. The significant environmental impact from the release of carbon from fossil fuels can take years to be redposited after being released, however the biogenic carbon cycle is much shorter-lived, because the carbon from fossil fuel origin are geologically trapped into deep soils.

In addition to estimate carbon capturing, some mitigation strategies and key indicators to drive  sustainble on-farm dairy production and its economic impact, was initiated in the first project. However, more focus on mitigation strategies and focus areas will be identified in this project which can be implemented and lower emissions even more. It is critical to note that these strageties will help farmers not only understand the GHG emisions, sources or sinks on farms, but help develop new and innovativbe strategies as time goes by to enable the full potential for regenerative farming. For example, the possibility of soil carbon to provide climate change mitigation and adaption benefits are very often described in the literature because of its abilities such as increasing N supply and plant available water holding capacity as well as greater pasture production yield. It is estimated that the potential reduction of C in the atomosphere can be in the range of 0.79 and 1.54 GtC per year with soil carbon sequestration.