Soil Erosion And Management Flashcards
What is soil erosion defined as being ?
The wearing away of the top layer of soil (topsoil)
Why is the topsoil the most fertile layer ?
Because it contained most organic nutrient rich materials.
Farmers want to protect this layer for growing crops and animal grazing.
How is soil eroded ?
Water and wind.
Water is worse
How much topsoil is lost every year ?
75 billion tonnes.
Equating to 9 million ha of productive land
How does repeated erosion reuse soil fertility?
Removal of topsoil which is rich in crop nutrients.
Reduction of depth of soil for rooting and water storage.
Reduced infiltration of water into soil and there fore increases run off and erosion
Excessive soil erosion can lead to what issues?
Loss of seeds / fertilisers/ pesticides.
Young plants being sandblasted.
Difficulty of field operations.
How can soil erosion damage surrounding environment ?
Deposition of sediment onto roads/ land / drains.
Damage to quality of water courses, lakes and rivers through increase in inputs / chemical loading
Increased run off - more flooding.
Sedminentaion damaging spawning grounds of fish
What is the aim to reduce water erosion but rainwater?
Reduce amount of surface flow.
Installing field drains/ ditches. Sediment should then be removed from ditches and replaced in fields where it came from.
Farmyard manure to stabilise topsoil.
Protecting soil in winter by early sowing or cover crops.
Work across slopes - reduces overland flow and forms rills / gullies
How do you control wind erosion of soil ?
Increasing soil cohesion bu applying organic matter like manure to soil - improves structure.
Increasing plant cover by 50%.
Increasing toughness of soil surface or leaving crop residues not ploughing them into soil.
Planting lines of trees/ hedgerows resting speed but also evaporation.
