C-arouNd: Refining Soil Conservation and Regenerative Practices to Enhance Carbon Sequestration and Reduce Greenhouse Gas Emissions

Summary in the original language of the document

While the last 60 years have seen significant progress in global food production with inorganic fertilizers, plant breeding, and pesticides, this has come at a cost to soil health. This intensive agriculture has led to a reduction in soil organic carbon (SOC) stocks, increased greenhouse gas (GHG) emissions, and ultimately contributed to global warming. Agriculture and land-use change are responsible for nearly 20% of global GHG emissions, making it a significant source of nitrous oxide (N2O) due to synthetic nitrogen fertilizers and methane (CH4) due to livestock activity and rice cultivation. This project aims to evaluate the influence of conservationist and regenerative agricultural
practices on carbon (C), nitrogen (N), and phosphorus (P) cycling, soil biodiversity, and GHG emissions, with a particular focus on long-term SOC stocks and the processes governing carbon persistence. To achieve this, the project has established a consortium of long-term field experiments that assess the impact of different cropping systems and agricultural practices on soil properties. Participants from
12 countries are involved, contributing a total of 37 field sites with varying chronosequences or contrasting agricultural management practices. At 26 sites established for at least 10 years, estimates and scenario models of potential N2O, CO2, and CH4 emissions from cropping, pasture, and forest systems will be generated using the best available IPCC or local emission factors. Additionally, GHG emissions will be directly measured at a subset of these sites. The project is building a global database of C and N stocks, bulk density, soil fertility, and GHG emissions across diverse ecosystems and under different agricultural management practices. This will allow researchers to determine how climatic conditions, net primary production of the cropping systems, and soil type influence C and N stocks, nutrient dynamics, and GHG emissions. The ultimate goal of the project is to recommend best management practices for food crop production that promote soil carbon accumulation, particularly mineral-associated organic matter (MAOM), without increasing GHG emissions. This will contribute to the long-term sustainability and resilience of agricultural systems. As promised in the project deliverables, the Long-Term Experiment (LTE) metadata has already been organized in a FAIR repository. Additionally, the protocols for soil sampling, laboratory analyses, and site characteristics are being prepared for publication. Furthermore, soil carbon sequestration is being quantified across all fields (or planned for future sampling), and in some experiments, greenhouse gas emissions are also being measured. This includes African dark earths and surrounding ecosystems, where both carbon sequestration and GHG emissions are being quantified. PhD students have also begun field trips to Norway for soil sampling.