SOIL

e- Outline the processess and consequences of soil degration

"Soil degradation occurs where our activities (either directly or indirectly) cause soil to become less vigorous or less healthy. Soil degradation results from changes to biological, geological or chemical components of a soil"

"A civilization bases its crops on "Fertile soil, a dependable water supply and relatively level land with reasonable rainfall which would not cause erosion (soil degradation)"

Some of the causes may be 

- Climatic conditions

- Causes like earthquakes, tornadoes or erosion can cause the minerals and nutrients to be removed from the soil
- This reduces the fertility of the soil and makes it less healthy to grow crops. 

- Salination

- "Salinity occurs through natural or human-induced processes that result in the accumulation of dissolved salts in the soil water to an extent that inhibits plant growth"(soil degradation) 

- Two main reasons of why salination occurs
       1. Weathering of materials that contain soluble salts. Weathering breaks down rocks and release these solutions. 
      2. The second reason is due to the deposition of oceanic salt carried through the wind and the rain. 

Over- Grazing

- "Overgrazing can occur under continuous or rotational grazing.  It can be caused by having too many animals on the farm or by not properly controlling their grazing activity.  Overgrazing reduces plant leaf areas, which reduces interception of sunlight and plant growth.  Plants become weakened and have reduced root length, and the pasture sod weakens".

- Human impacts (population growth, farming techniques)
- Over irrigating: Putting too much water removes the minerals from the soil and weakens it.
- Mismanaging the usage of soil and rather exploiting the land
- Overplanting lots of times makes the soil less strong and resistant. 
- Too much plowing 

Every soil is different, however, each one should be treated correctly in order for it to last a long time without loosing its minerals and nutrients.