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| What is salinization? |
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| It is a process of enrichment of a soil in soluble salts which results in the formation of a salt-affected soil. |
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| How is salinization a problem? |
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Salinization causes: - an increase in osmotic pressure which makes water mobilization more difficult for plants;
- toxicity of certain ions to plants (Cl-, Na+, etc.);
- degradation of the soil (changes in structural state, reduction of hydraulic conductivity, etc.).
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| Is it a serious problem today? |
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| Globally The world is losing, on average, 10 hectares of land suitable for cultivation every minute, of which 3 hectares is as a result of salinization (equivalent to 1.5 Mha per year) [Kovda, 1983]. Today it is estimated that almost 400 Mha are affected by salinization [Bot, Nachtergaele and Young, 2000]. In Africa... almost 40 Mha are affected by salinization, around 2% of the total surface area. In the Near East... almost 92 Mha are affected by salinization, around 5% of the total surface area. Access to specific data for some African countires and the Near East... |
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| What are the causes of land salinization? |
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| 80% of salt-affected land has a natural origin. Thus the use of the term “primary” salinization, due to salts formed by weathering of rocks or natural external inputs. 20% of salt-affected land, around 15 Mha on the continent of Africa alone, have a "man-made" origin. Thus the use of the term "secondary" salinization, introduced by human activity linked to agricultural practices, and in particular to irrigation. |
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