Environmental resource management

Land use, land-use change and forestry

Climate change

Soil water

Tillage

Biology

Soil science

Global change

Geography

Ecology

Land use

Climate change mitigation

Environmental science

Soil carbon

Agroforestry

Land management

Global Change Biology

Major drivers of gains or losses in soil organic carbon (SOC) include land management, land‐use change, and climate change. Thousands of original studies have focused on these drivers of SOC change and are now compiled in a growing number of meta‐analyses. To critically assess the research efforts in this domain, we retrieved and characterized 192 meta‐analyses of SOC stocks or concentrations. These meta‐analyses comprise more than 13,200 original studies conducted from 1910 to 2020 in 150 countries. First, we show that, despite a growing number of studies over time, the geographical coverage of studies is limited. For example, the effect of land management, land‐use change, and climate change on SOC has been only occasionally studied in North and Central Africa, and in the Middle East and Central Asia. Second, the meta‐analyses investigated a limited number of land management practices, mostly mineral fertilization, organic amendments, and tillage. Third, the meta‐analyses demonstrated relatively low quality and transparency. Lastly, we discuss the mismatch between the increasing number of studies and the need for more local, reusable, and diversified knowledge on how to preserve high SOC stocks or restore depleted SOC stocks.

A global overview of studies about land management, land‐use change, and climate change effects on soil organic carbon