Weathering
The breakdown of rocks by climate, chemicals, plants and animals.
Humus
Organic material from the remains of plants and animals needed to make fertile soil.
Fertility
Describes the quality of a soil and its ability to produce good crops.
Soil erosion
the removal and loss of soil mainly by wind, rain and running water.
Deforestation
The cutting down and burning of trees to clear large areas of the forest.