Soil Degradation

Primary reference(s)

FAO, 2020. FAO Soils Portal Key definitions. Food and Agriculture Organization of the United Nations (FAO). Accessed 2 October 2024.

Annotations

Key relevant UN convention / multilateral treaty

United Nations Convention to Combat Desertification (UNCCD), (UNCDD, 1994);

United Nations Convention for Biological Diversity;

United Nations Framework Convention on Climate Change.

Drivers

Anthropogenic drivers of soil degradation include increasing consumer demand, urbanization, industrialization, and competition for land. These in turn result in a range of pressures such as intensive agriculture (imbalance fertilization, over-tillage), soil sealing, soil salinization by irrigation, deforestation, wildfires and pollution. Air pollution can affect semi-natural areas and urban soils, where the risk management is focused on waste streams or industrial emissions. Studies on antibiotics in the soil environment have revealed that antimicrobials affect soil microbiomes which in turn may affect their quality, driving soil degradation (Cycoń et al., 2019). 

Climate-related drivers of land or soil degradation include short-intensive rainstorms to gradual increases in temperature, precipitation and wind (Olsson et al., 2022). Climate change is amplifying soil degradation through increasing temperature, changing rainfall patterns and intensification of rainfall (Olsson et al., 2022).

Impacts

Soil degradation can lead to increased soil erosion, loss of organic matter, nutrient depletion, accumulation of salts and harmful contaminates, and reduction in biodiversity (Soil Atlas, 2024). Around 30% of the worlds soils are moderately to highly degraded. Forty percent of these degraded soils are located in Africa and most of the rest are in areas that are afflicted by poverty and food insecurity (Soil Atlas 2024). It is estimated that at least 60% of the soils of the EU are affected by one or more degradational process (EU Soil Observatory, 2024).  

Most future land degradation is predicted to occur in the areas with the largest amount of arable land remaining. If current trends continue, experts estimate that by 2050, more than 90% of the Earth’s land areas will be substantially degraded, 4 billion people will live in drylands, 50–700 million people will be forced to migrate, and global crop yields will be reduced by an average of 10% and up to 50% in some regions (Nachtergaele et al., 2012 cited by Little, 2019; IUCN, 2015; Gomiero, 2016; IPBES, 2018).

Multi-hazard context

The figure below summarises common interactions between soil degradation and other hazards. This information should be used with caution and not be solely relied upon in Disaster Risk Management, particularly as some interactions may not have been included. Note that hazardous events occurring together or locally in space or time may not necessarily cause, amplify or be otherwise related to each other. Specific examples of multi-hazard context can be found in the ‘Hazard drivers’ and ‘Impacts’ sections above.

Multi-hazard diagram

Risk Management

For agricultural soils, risk management through agroecology is adopted, which starts by restoring soil life to re-establish and/or enhance the multiple soil-based biological processes (FAO, 2015). This requires: 

• Increasing and monitoring soil organic matter: Soil organic matter is considered the most common deficiency in degraded mineral soils and the main indicator for soil quality. Practical, accessible indicators can support local decisions and larger landscape monitoring and analyses for district level implementation.
• Facilitating and monitoring of soil biodiversity: Soil biological communities are directly responsible for multiple ecosystem functions.
• Building on local farmers’ knowledge: Participatory scientific approaches to soil ecosystem management, such as Farmer Field Schools, are of great importance to inform farmers’ knowledge with researchers’ scientific principles in order better locally adapt agroecological systems.
• Wholescale adoption of sustainable soil management practices. 

Agroforestry systems can reduce soil erosion by as much as 100 times on steep slopes. Growing Faidherbia albida in association with millet (Pennisetum glaucum) increased grain yields by 50% in Burkina Faso and Senegal. In Honduras the adoption of soil conservation practices tripled or quadrupled maize yields for 1200 families (FAO, 2015). 

The FAO and its Global Soil Partnership launched a new program to boost soil productivity and reduce soil degradation for greater food and nutrition security in Africa. The recently adopted Africa Union Soil Initiative for Africa provides a long-term framework to guide investments and efforts to improve the health and resilience of Africa's soil (FARA, 2020). 

Monitoring

The section and the table below offer an overview of monitoring soil degradation. This information can be used for forecasting within a national early warning system (EWS). Since EWS capacities and processes differ across countries, the most current and specific information regarding EWS should be obtained from the appropriate national or regional agency/authority responsible for disaster management.