Francaviglia, R., Di Bene, C., Farina, R., Salvati, L., Vicente-Vicente, J. L.

Assessing “4 per 1000” soil organic carbon storage rates under Mediterranean climate: a comprehensive data analysis

in Mitigation and Adaptation Strategies for Global Change, 08.01.2019

Peer Review , Sustainable Resource Management and Global Change

Soil Organic Carbon (SOC) is considered a proxy of soil health, contributing to food
production, mitigation, and adaptation to climate change and other ecosystem services.
Implementing Recommended Management Practices (RMPs) may increase SOC stocks,
contributing to achieve the United Nations Framework Convention on Climate Change 21st
Conference of the Parties agreements reached in Paris, France. In this framework, the “4 per
1000” initiative invites partners implementing practical actions to reach a SOC stock annual
growth of 4‰. For the first time, we assessed the achievement of 4‰ objective in Mediterranean
agricultural soils, aiming at (i) analyzing a representative data collection assessing
edaphoclimatic variables and SOC stocks from field experiments under different managements
in arable and woody crops, (ii) providing evidence on SOC storage potential, (iii) identifying
the biophysical and management variables associated with SOC storage, and (iv)
recommending a set of mitigation strategies for global change. Average storage rates amounted
to 15 and 80 Mg C ha−1 year−1 × 1000 in arable and woody crops, respectively. Results show
that application of organic amendments led to significantly higher SOC storage rates than
conventional management, with average values about 1.5 times higher in woody than in arable
crops (93 vs. 63Mg C ha−1 year−1 × 1000). Results were influenced by the initial SOC content,
experiment duration, soil texture, and climate regime. The relatively lower levels of SOC in
Mediterranean soils, and the high surface covered by woody crops, may reflect the high
potential of these regions to achieving significant increases in SOC storage at the global scale.