Deutsch: Landdegradation/Bodendegradation, Español: Degradación de la tierra, Português: Degradação do solo/Degradação da terra, Français: Dégradation des terres, Italiano: Degrado del suolo/Degradazione del territorio
Land Degradation in the environmental context refers to the reduction or complete loss of the biological or economic productivity and complexity of rainfed cropland, irrigated cropland, range, pasture, forest, and woodlands. It is a process driven by a combination of human-induced activities and natural factors, leading to the deterioration of soil health, vegetation cover, and ecosystem function.
Definition and General Significance
Land degradation is a major global environmental and socio-economic challenge:
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Reduced Capacity: The degraded land loses its capacity to provide essential ecosystem services such as producing food, absorbing and filtering water, and sequestering carbon.
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Socio-Economic Impact: It directly affects food security, exacerbates poverty in rural areas, and can lead to mass migrations and resource conflicts, particularly in arid and semi-arid regions.
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Key Processes: Degradation includes a variety of phenomena, most notably soil erosion, chemical contamination, salinization, and loss of vegetation cover.
Important Aspects to Consider
Understanding the drivers and forms of degradation is crucial for effective intervention:
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Soil Erosion: The displacement of the uppermost, most fertile layer of soil (topsoil) by wind or water. This is often accelerated by unsustainable farming practices like excessive tilling, monoculture, and deforestation.
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Chemical Degradation: This includes the loss of essential soil nutrients due to intensive farming without proper replenishment, or contamination by pollutants (heavy metals, pesticides) and acidification (often from acid rain or excessive use of nitrogen fertilizers).
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Physical Degradation: This involves the deterioration of the soil's structure, such as compaction (due to heavy machinery), which reduces water infiltration, aeration, and root penetration, severely impeding plant growth.
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Desertification: A specific form of land degradation occurring in dryland areas, where the land turns into desert-like conditions due to climate variation and unsustainable human activities. This is primarily the result of overgrazing and poor irrigation practices.
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Interlinkage with Climate Change: Land degradation both contributes to and is exacerbated by climate change. Degraded soils release stored carbon (contributing to emissions), while climate change (e.g., increased drought and heavy rainfall) accelerates erosion and reduces soil moisture.
Examples
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Salinization: In arid regions where irrigation is practiced without adequate drainage, water evaporates, leaving behind concentrated salts that accumulate in the topsoil, rendering the land unsuitable for most crops.
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Deforestation for Grazing: The clearing of tropical rainforests for cattle ranching, which quickly strips the thin, nutrient-poor soil of its protective cover, leading to massive erosion and nutrient leaching.
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Laterization: A process in tropical soils where excessive leaching removes silica, leaving behind iron and aluminum oxides that harden the soil into an impermeable layer, making cultivation impossible.
Recommendations
Reversing land degradation requires integrated, long-term land management:
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Sustainable Land Management (SLM): Implement practices such as conservation tillage (no-till farming), terracing on slopes, agroforestry (integrating trees into farmlands), and crop rotation to restore soil structure and fertility.
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Afforestation and Reforestation: Plant trees and restore natural vegetation cover, especially on degraded slopes and marginal lands, to stabilize soil, reduce wind erosion, and sequester carbon.
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Water Harvesting and Management: Employ techniques such as bunds, check dams, and strategic contour plowing to capture and retain rainwater in the soil, preventing runoff and increasing soil moisture.
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Policy and Governance: Support land tenure security, which incentivizes long-term sustainable management by local communities and farmers, and enforce regulations against industrial pollution and illegal deforestation.
Related Terms
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Soil Erosion
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Desertification
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Ecosystem Services
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Sustainable Land Management (SLM)
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Topsoil
Summary
Land degradation is the reduction or total loss of the biological and economic productivity of land, driven primarily by human misuse (e.g., unsustainable farming, deforestation). It encompasses processes like soil erosion, chemical contamination, and compaction, severely diminishing the land's ability to provide ecosystem services. Key aspects include its strong link to poverty and food insecurity and its reciprocal relationship with climate change. Recommendations center on widespread adoption of Sustainable Land Management (SLM) practices, reforestation, and effective water harvesting techniques.
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