We talk about CO₂, plastic and species extinction — but right beneath our feet, a crisis is unfolding that hardly anyone notices. Around the world, fertile soils are becoming increasingly saline. What sounds harmless at first threatens crops, ecosystems and ultimately our food supply. How did it come to this? And why did earlier generations know methods that often prevented this problem?
© pixabay / Betty VerheijWhen fertile soil becomes saline
Salt belongs in the ocean — not on our fields. Yet today, billions of hectares of land worldwide are affected by or at risk of salinization. The causes are mostly human-induced: intensive irrigation without adequate drainage, rising temperatures, longer droughts and falling groundwater levels. When water evaporates from the surface, the salts dissolved in it remain behind. With each irrigation cycle, their concentration increases slightly. The Food and Agriculture Organization of the United Nations (FAO) warns that this process is being further accelerated by climate change.
Ancient knowledge that was almost lost
Although farmers in the past didn’t have modern technology, they did have a wealth of experience. They rotated crops, left fields fallow, enriched soils with organic matter and adapted their irrigation practices to the climate and soil conditions. In many regions, sophisticated canal and drainage systems prevented the permanent accumulation of salts. With the industrialization of agriculture, some of this local knowledge was pushed into the background. Higher yields often took precedence over long-term soil health.
The consequences extend far beyond agriculture
Salinized soil retains less water; plants grow poorly or die off entirely. As a result, insects, birds and other animals lose their habitats. At the same time, soil erosion increases and agricultural productivity declines. For millions of people, this means smaller harvests, rising food prices and growing food insecurity. According to estimates, this results in economic losses amounting to billions every year.
© unsplash / Gabriel Jimenez
© unsplash / Markus SpiskeCan the situation still be salvaged?
Yes — and the solutions have long been known. Modern drip irrigation significantly reduces water consumption and salt buildup. Improved drainage systems, salt-tolerant crops, cover crops and the build-up of humus help restore soil resilience. At the same time, researchers are working on new plant varieties that deliver high yields even under saline conditions. International programs run by the FAO and the UNCCD support countries in restoring degraded soils.
Bottom line
Healthy soils take centuries to form — but can be destroyed in just a few decades. Increasing soil salinization shows how closely agriculture, water, and climate are interconnected. The good news: Unlike many environmental problems, soil salinization is often reversible if action is taken in time.
Ressources
- Global Soil Partnerschip: Food and Agriculture Organization of the United Nations (FAO)
- The global threat of drying lands: Regional and global aridity trends and future projections: UN Convention to Combat Desertification
- Farming and Agribusiness: World Bank Group
- Soil Health: Natural Resources Conservation Service
- Soil Salinization: ScienceDirect