Soil erosion Flashcards
1
Q
What is erosion
A
Wearing away of topsoil
2
Q
How much productive land lost annually
A
9m ha
3
Q
What is the main cause
A
Water erosion. Rill erosion: small channels. River bank erosion: meanders erose soil. Sheet erosion: uniform topsoil loosened. Gully erosion: ditches from rills
4
Q
What is the other cause
A
Wind erosion. Saltation, creep, abrasion, suspension
5
Q
Erosion issues
A
Reduce infiltration, fertility, and depth. Sandblasting. River sediment damages fish spawning
6
Q
Control of erosion
A
Install field drains, manure stabilises topsoil, contour ploughing, cover crops
7
Q
Erosion control example
A
Burkina Faso: sorghum stubble cut 1m above surface to trap material and lower speed
