FAO’s Global Status of Salt-Affected Soils report 2024

The FAO’s Global Status of Salt-Affected Soils report, released on December 11, 2024, sheds light on the critical issue of soil salinity and its impact on global land use, agriculture, and food security.

Definitions

• Salt-affected soils are a specific group of soils that have elevated amounts of soluble salts (saline soils) or exchangeable sodium (sodic soils) that adversely affect the growth of most plants.

Key Findings:

• Extent of Salt-Affected Soils:
  • Approximately 1.4 billion hectares, or 10.7% of the global land area, are salt-affected.
  • Salt-affected soils encompass 10% of irrigated cropland and 10% of rainfed cropland, threatening agricultural productivity and food security.
• Geographic Distribution:
  • Top Countries with Salt-Affected Areas:
    • Australia: 357 million hectares (mha)
    • Argentina: 153 mha
    • Kazakhstan: 94 mha
  • Countries Most Severely Affected (percentage of total land area):
    • Oman (93.5%), Uzbekistan (92.9%), and Jordan (90.6%).
• India’s Salt-Affected Soils:
  • 6.72 million hectares (2.1% of India’s total land area) are salt-affected, including:
    • 2.95 mha saline soils
    • 3.77 mha sodic soils
  • States contributing to 75% of the salt-affected soils:
    • Gujarat (2.23 mha), Uttar Pradesh (1.37 mha), Maharashtra (0.61 mha), West Bengal (0.44 mha), and Rajasthan (0.38 mha).

Causes of Soil Salinisation:

• Natural Factors:
  • Arid climates with low rainfall.
  • Natural accumulation of salts in soil through weathering processes.
  • Rising sea levels leading to coastal salinisation.
• Human-Induced Factors:
  • Irrigation Practices: Over-irrigation and poor drainage exacerbate salinity by bringing salts to the surface.
  • Agricultural Practices: Excessive use of chemical fertilizers and poor crop management.
  • Climate Crisis: Increasing aridity, freshwater scarcity, and more frequent droughts.

Implications:

• Food Security:
  • Soil salinity reduces fertility, negatively impacting crop yields, particularly in countries already vulnerable to food insecurity.
  • Developing countries are at the highest risk due to limited resources for mitigation.
• Environmental Sustainability:
  • Salinity contributes to land degradation, reducing biodiversity and ecosystem services.
  • Coastal regions face dual risks from salinity and flooding due to sea-level rise.

Recommendations:

• Sustainable Land Management:
  • Improved irrigation techniques (e.g., drip irrigation) and drainage systems.
  • Adoption of salt-tolerant crop varieties.
• Policy and Investment:
  • Government and international organizations need to invest in soil health programs.
  • Incentivizing farmers to adopt sustainable practices.
• Research and Monitoring:
  • Ongoing geospatial mapping of salt-affected soils.
  • Climate-resilient agricultural research and soil reclamation projects.