1. Land degradation is a process in which the value of the biophysical environment is affected by a combination of human-induced processes acting upon the land.
2. It is viewed as any change or disturbance to the land perceived to be deleterious or undesirable. Natural hazards are excluded as a cause; however human activities can indirectly affect phenomena such as floods and bush fires. This is considered to be an important topic of the 21st century due to the implications land degradation has upon agronomic productivity, the environment, and its effects on food security.
3. It is estimated that up to 40% of the world’s agricultural land is seriously degraded.
4. Land degradation is a global problem largely related to agricultural use. Causes include:
– Land clearance, such as clear cutting and deforestation
– Agricultural depletion of soil nutrients through poor farming practices
– Livestock including overgrazing and overdrafting
– Inappropriate irrigation and overdrafting
– Urban sprawl and commercial development
– Vehicle off-roading
– Quarrying of stone, sand, ore and minerals
– Increase in field size due to economies of scale, reducing shelter for wildlife, as hedgerows and copses disappear
– Exposure of naked soil after harvesting by heavy equipment
– Monoculture, destabilizing the local ecosystem
– Dumping of non-biodegradable trash, such as plastics
– Invasive Species
– Soil degradation
– Soil contamination
– Soil erosion
– Soil acidification and
– Loss of soil carbon
5. Significant land degradation from seawater inundation, particularly in river deltas and on low-lying islands, is a potential hazard that was identified in a 2007 IPCC report.
6. As a result of sea-level rise from climate change, salinity levels can reach levels where agriculture becomes impossible in low-lying areas.