Soil erosion Flashcards
What is soil?
Soil is a valuable resource and it is a medium in which plants are grown
Plants are…. & man cannot….?
Plants are producers &
Man cannot produce their own food ( we are so lazy fr)
What does man depend on?
Man depends either directly or indirectly on plants as a source of energy. Therefore the study of soil and those characteristics which affect plant growth are important.
List the causes of soil erosion- (6)
1) Occurs when the topsoil/surface layer of soil is removed
2) Deforestation
3) Poor farming methods
4) Trampling of soil
5) Clearing of land for squatting
6) Overgrazing by animals
What does natural vegetation do? (Deforestation)
Natural vegetation covers and protects the topsoil from the elements: being blown away by the wind, or disturbed by heavy rainfall
What are soil particles bound together by? (Deforestation)
Soil particles are also bound together by root systems
List some ways vegetation can be removed and also what does it cause? (Deforestation)
When vegetation is removed, by the felling of trees, overcutting, overgrazing; topsoil is left bare and exposed
What happens when the sun’s rays fall directly on the soil? (Deforestation)
Sun’s rays fall directly on the soil an dries up the humus and evaporates soil water
What is dry soil more susceptible to? (Deforestation)
Dry soil is more susceptible to being blown away and eroded
What do heavy drops of rainfall disturb? (Deforestation)
Heavy drops of rainfall disturb the crumb structure
What happens to the soil which is disturbed and loosened by heavy rainfall? (3)
1) it is sometimes washed away into rivers and waterways.
2) Rivers tend to become choked with silt and overflow their banks.
3) This process occurs when soil from sloping areas is eroded.
Give a poor farming method (1)
Ploughing loosens the soil and destroys its natural structure
Give a poor farming method (2)
Failure to replace hummus after successive crop cycles and burning weed (wheyyyy farmers them rel Wildin) reduces the water holding capacity of the soil.
Give a poor farming method (3)
Burnt soil dries up easily and is susceptible to wind erosion
Too many animals in a small area of land… and (i.e)…?
(overgrazing 1)
will not make economic use of the grass/food they consume, as their growth rate will be too slow
(i.e) too many animals in a small area would not grow quickly because of the competion for food
