Most cited article - PubMed ID 35778395
Global stocks and capacity of mineral-associated soil organic carbon
Soil has garnered global attention for its role in food security and climate change. Fine-scale soil-mapping techniques are urgently needed to support food, water, and biodiversity services. A global soil dataset integrated into an Earth observation system and supported by cloud computing enabled the development of the first global soil grid of six key properties at a 90-m spatial resolution. Assessing them from environmental and socio-economic perspectives, we demonstrated that 64% of the world's topsoils are primarily sandy, with low fertility and high susceptibility to degradation. These conditions limit crop productivity and highlight potential risks to food security. Results reveal that approximately 900 Gt of soil organic carbon (SOC) is stored up to 20 cm deep. Arid biomes store three times more SOC than mangroves based on total areas. SOC content in agricultural soils is reduced by at least 60% compared to soils under natural vegetation. Most agricultural areas are being fertilized while simultaneously experiencing a depletion of the carbon pool. By integrating soil capacity with economic and social factors, we highlight the critical role of soil in supporting societal prosperity. The top 10 largest countries in area per continent store 75% of the global SOC stock. However, the poorest countries face rapid organic matter degradation. We indicate an interconnection between societal growth and spatially explicit mapping of soil properties. This soil-human nexus establishes a geographically based link between soil health and human development. It underscores the importance of soil management in enhancing agricultural productivity and promotes sustainable-land-use planning.
- Keywords
- carbon sequestration, digital soil mapping, remote sensing, soil health, soil security,
- Publication type
- Journal Article MeSH
Plant diversity can alter soil carbon stocks, but the effects are difficult to predict due to the multitude of mechanisms involved. We propose that these mechanisms and their outcomes can be better understood by testing how plant diversity affects particulate organic matter (POM) and mineral-associated organic matter (MAOM) depending on whether MAOM storage is "saturated" and the total soil organic matter pool is limited by plant inputs. Such context-dependency of plant-diversity effects on POM, MAOM, and total soil organic matter helps explain inconsistencies in plant-diversity-soil-carbon relationships across studies. Further illumination of this context-dependency is required to better predict consequences of biodiversity losses and gains, and manage ecosystems as carbon sinks and nutrient stores.
- MeSH
- Biodiversity * MeSH
- Ecosystem MeSH
- Minerals * analysis chemistry MeSH
- Organic Chemicals * analysis MeSH
- Particulate Matter * analysis MeSH
- Soil * chemistry MeSH
- Plants * metabolism classification MeSH
- Carbon Sequestration MeSH
- Carbon analysis MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
- Names of Substances
- Minerals * MeSH
- Organic Chemicals * MeSH
- Particulate Matter * MeSH
- Soil * MeSH
- Carbon MeSH
Much research focuses on increasing carbon storage in mineral-associated organic matter (MAOM), in which carbon may persist for centuries to millennia. However, MAOM-targeted management is insufficient because the formation pathways of persistent soil organic matter are diverse and vary with environmental conditions. Effective management must also consider particulate organic matter (POM). In many soils, there is potential for enlarging POM pools, POM can persist over long time scales, and POM can be a direct precursor of MAOM. We present a framework for context-dependent management strategies that recognizes soils as complex systems in which environmental conditions constrain POM and MAOM formation.
