Project Summary

With the use of inorganic fertilizers, plant breeding and pesticides, global food production more than tripled in the last 60 years, reducing hunger and poverty by fulfilling the Sustainable Development Goals from the UN 2030 Agenda. However, this progress came at a cost because soil degradation resulted in a reduction of soil organic carbon (SOC) stocks and an increase in greenhouse gas (GHG) emissions and global warming. Agriculture and land use change are collectively responsible for nearly 20% of global greenhouse gas (GHG) emissions, making it one of the most significant contributors to nitrous oxide (N2O) and methane (CH4) emissions. Nitrous oxide arises primarily from the application of synthetic nitrogen fertilizers, while methane emissions result from livestock activity and paddy rice cropping. Promoting agricultural practices that enhance soil carbon stocks and decrease greenhouse gas (GHG) emissions is essential for mitigating global warming. Recognizing this, international initiatives such as the 4per1000 were launched during the COP21 meeting in Paris (2015) with the aim of encouraging the adoption of agricultural practices that boost soil carbon stocks as a strategy for mitigating global warming on a global scale. Moreover, increasing SOC will have positive effects on agricultural production due to increase nutrients and water cycling, and on soil health due to its positive relationship with soil biodiversity. The objective of this proposal is 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 emphasis on long-term SOC stocks, and processes governing C persistence.
C-arouNd project represents an exploratory effort to couple the stoichiometric drivers to microbial populations related to C, N, and P cycling and stocks, and GHG emission under diverse agricultural practices. For this, we are establishing a consortium of long-term field experiments that evaluate the impact of different cropping systems and agricultural practices on soil properties. There are participants from 12 different countries (Figure 1) with a total of 40 field sites with different chrono-sequences or contrasting agricultural management.

Figure 1. Field sites network C-arouNd: See soil C and N around the world.


At 26 sites established for at least 10 years. At each site, estimates and scenarios modeling of possible emissions of N2O, CO2 and CH4 from the cropping/pasture/forest systems will be made using the best-available IPCC or local emission factors and GHG emissions will be measured at a subset of sites. To compare the impact of different climatic and edaphic conditions among sites, we propose a standard soil organic matter (OM) physical fractionation procedure resulting in two contrasting soil fractions including particulate organic matter (POM), which consists mainly of partially decomposed plant residues, and the mineral-associated OM (MAOM), principally of microbial origin. C-arouNd project will build a worldwide database of C and N stocks, bulk density, soil fertility and GHG emissions across different ecosystems and under differential agricultural management (Figure 2). Furthermore, C-arouNd will determine to what extent climatic conditions, net primary production of the cropping systems and soil type affect C and N stocks, nutrient dynamics and GHG emissions. The final product of the C-arouNd project will be to recommend best management practices for production of food crops which would promote soil C accumulation, especially MAOM, without increasing GHG emissions thus contributing to the sustainability and resilience of agriculture.

Figure 2. A systems framework at world level (with number of sites in each continent).