Global Soil Partnership

Novel initiative to map Salt-Affected Soils globally


Salt-affected soils (SAS) are a group of soils with high content of neutral salt and/or sodium ions. The salts hold water and nutrient in soil at high tension, which make these vital components practically unavailable for plants at the rootzone. Consequently, they limit plant growth and development of many salt intolerant crops. SAS are not desirable in agriculturally productive areas. Development of SAS in these areas causes a significant decline in crop productivity, water quality and soil biodiversity. The ripple effect of these impacts threatens the global food security and hinder the achievement of the Sustainable Development Goals (SDGs).


To support sustainable management of SAS and control of the spread in agriculture areas, the FAO-GSP initiative is coordinating the development of the Global Soil Salinity Map (GSSmap) to update the global and country-level information on salt-affected soils and lay ground for future periodic monitoring of these soils. The objective of the GSSmap is to produce a country-driven map that provides a global assessment on salt-affected areas, provides a baseline for monitoring SAS and improves national capacities on SAS management.  GSSmap will be the first update of a country-driven global map of SAS since the publications of global distribution of SAS in the early 1980s.


The process is supported by a comprehensive capacity development programme which supports member countries to produce their national datasets. A capacity building toolkit has been prepared which outline input data requirements, data preparation, and soil information products to contribute to the global update of salt-affected soils. GSP is using this toolkit to support national experts to produce soil information for evidence-based decision making. The toolkit includes the following:

  1. Country guidelines 
  2. Lesson 1: Requirements for capacity building
  3. Lesson 2: Data preparation and software installation 
  4. Lesson 3: Spatial modelling of soil properties 
  5. Lesson 4: Spatial modelling of salt-affected soils 
  6. Technical manual 
  7. QGIS (GIS Software)
  8. ILWIS (GIS Database)
  9. R (Modelling and computing software)

The capacity development effort aims at: (1) building consistent and updated national and regional soil information systems to contribute to Global Soil Information System (GloSIS); (2) Share and transfer soil knowledge and new technology within and beyond the region; (3) Provide soil information to all those with interest in sustainable soil and land management; and (4) train a new generation of experts in soil science, digital soil mapping and sustainable soil management.


Capacity building workshop on mapping salt-affected soils in Eurasian countries was held at the International Agricultural Research and Training Center Menemen in Izmir, Turkey from 2nd to 7th March 2020. The workshop was collaboratively organized by the GSP, FAO Sub-Regional Office for Central Asia, the Government of Turkey through the Ministry of Agriculture and Forestry, General Directorate of Agricultural Research and Policies, and the Eurasian Soil Partnership. More than 20 participants attended the workshop from 9 countries including Armenia, Azerbaijan, Georgia, Kazakhstan, Kyrgyzstan, Moldova, Tajikistan, Turkey and Ukraine. The workshop goal was to mobilize and support Eurasian countries to develop their national information of salt-affected soils and then contribute to the global information update on salt-affected soils. The participants learnt the methodological steps for data preparation, digital soil mapping, and mapping of salt-affected soils. They successfully completed the training course and are now in the second phase of improving their national maps using the skills gained during the training.


The two-weeks online capacity building on digital soil mapping (DSM) of salt-affected soils in the Asian countries was carried out between 24th March and 3rd April 2020. The training was organized by the FAO-GSP, Asian Soil Partnership, and the Rural Development Administration of the Republic of Korea through the Asian Food and Agriculture Cooperation Initiative (AFACI). AFACI is an inter-governmental and multi-lateral cooperation initiative aiming to improve food production, realization of sustainable agriculture and enhancement of extension service in Asian countries by sharing knowledge and information on agricultural technology. The online training innovatively overcame the global lockdown crisis through virtual interaction while successfully meeting its objective of mobilizing and supporting the Asian countries to develop their national information on soil properties and salinity using the DSM technique. More than 60 participants attended the training daily from 16 Asian countries including Afghanistan, Bangladesh, Bhutan, Cambodia, India, Indonesia, Kyrgyzstan, Laos, Mongolia, Myanmar, Nepal, Pakistan, Philippines, Republic of Korea, Sri Lanka, Thailand and Viet Nam. The participants acquired new skills and tools for data preparation, DSM techniques, and spatial modelling of soil salinity. They will use these skills and tools to start developing national soil and soil salinity maps for their countries and contribute to the update of global information on salt-affected soil.


An online meeting between national experts on salt-affected soils in the Latin America and the Caribbean (LAC) was organized to kickstart the capacity building program and national mapping of salt-affected soils in the LAC region. The online convening brought together forty (40) participants from the Latin American countries and the Caribbean Island States of Argentina, Brazil, Bolivia, Colombia, Ecuador, Paraguay, Peru, Uruguay, Venezuela, Costa Rica, Dominican Republic, El Salvador, Guatemala, Honduras, Nicaragua, Trinidad and Tobago, Jamaica and Belize on the 24th March (in English) and on the 25th March 2020 (in Spanish). The meeting was organized by GSP and the LAC Soil Partnership. The goal of the meeting was to mobilize the countries in the LAC region and discuss the progress with input data preparation towards the development of national information on salt-affected soils. The participants expressed a consensus on way-forward and the need to start the capacity building exercise from mid-April 2020.