The importance of soil organic carbon (SOC) management and monitoring has been widely recognized in the context of climate change mitigation, adaptation and food security. Though manifold studies on SOC measurement and sequestration have been published, an interdisciplinary focus to promote large-scale application is rare and there exists a clear bias towards northern and western countries. The Global Symposium on SOC held at FAO in March 2017, co-organized by FAO, GSP/ITPS, UNCCD-SPI, IPCC and WMO, succeeded in bringing scientists and policy makers from 111 countries together to exchange knowledge on and review the potential of possible implementation paths to maintain and/or increase SOC in all the regions of the world to achieve the multiple objectives of climate change mitigation and adaptation, food security and land degradation neutrality. This special issue of SOIL is one of the outcomes of the symposium.

The effect of agricultural management and land use on SOC and the challenges related to the preservation and accrual of SOC stocks will be presented from three different regional perspectives: tropical soils in sub-Saharan Africa, drylands with a focus on the Near East and North Africa, and the subhumid South American Chaco. Contributions related to measuring and monitoring SOC will elaborate on emerging technologies to account for SOC and C balances, namely proximal sensing and isotopic partitioning techniques. SOC assessment and mapping studies on national scales show and test the use of different methods depending on data availability and environmental conditions while at the same time stressing the need to strengthen technical capacities for improving the estimations and reporting of SOC stocks on a country basis. Also, an innovative approach, which includes socio-economic assessments and stakeholder engagement processes, is part of this special issue. A concept for the establishment of laboratory networks will also be presented to highlight the importance of harmonization to move towards more solid and accurate assessments of SOC stocks within and between countries over time. The special issue aims at providing different perspectives from different regions with heterogeneous resources and priorities that have, nevertheless, the common goal of preserving and, wherever possible, increasing the SOC stocks.