Step 1: Sort the causes into natural pressure and human pressure.
Natural pressure includes wind and water erosion in dry and hilly tracts. Human pressure includes clearing forests, overstocking pastures with animals, digging mines, and farming the land harder than it can bear.
Step 2: Connect each human cause to its effect on land.
Removing tree and grass cover exposes soil to erosion; digging mines strips soil directly; heavy irrigation without drainage raises the water table and brings salts to the surface, making land unfit for crops.
Final Answer:
Land degradation in India comes mainly from deforestation, overgrazing, mining and industrial damage, and poor irrigation and farming practices, working alongside natural erosion.$\boxed{\text{Human land-use pressure plus natural erosion}}$