Question

what are the main causes of land degradation?

Answer 1

Land degradation is a global problem largely related to agricultural use. The major causes include:

Land clearance, such as clearcutting and deforestation 
Agricultural depletion of soil nutrients through poor farming practices
Livestock including overgrazing and overdrafting Inappropriate irrigation
 and overdrafting Urban sprawl
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
Soil degradation, e.g.Soil contamination, Soil erosion, Soil acidification, Loss of soil carbon