Soil Erosion Degradation Soil erosion movement of soil
- Slides: 24
Soil Erosion & Degradation Soil erosion: movement of soil components, especially litter & topsoil, from one place to another. • losing topsoil makes soil less fertile & less able to hold water; • while soil is a potentially renewable resource, it takes long periods of time to form topsoil, typically 200– 1000 years to form 2. 5 centimeters (1 inch) of topsoil; • topsoil is eroding faster than it forms in about one
Soil Erosion & Degradation Major areas of the world are threatened by serious soil erosion.
Soil Erosion & Degradation • Farming practices such as plowing and tilling can leave soil uncovered and loose. • These practices leaves soil vulnerable to water and wind Disk Harrow erosion. Tilling
Soil Erosion & Degradation: Wind & Water
Soil Erosion & Degradation
Dust Bowl During the 1930 s, a combination of drought & poor soil conservation led to severe wind erosion of topsoil in what is known as the Dust Bowl of the Great Plains.
Desertification of arid & semiarid lands results when land productivity drops markedly. Causes: • overgrazing; • deforestation & devegetation; • surface mining; • poor irrigation techniques; • salt buildup; • farming on unsuitable terrain; • soil compaction by farm machinery.
Dust Storms Dust Devil
Dust Storms
Dust Storms
Dust Storms Asia Saudi Arabia Sahara
Problems of Irrigation: Salinization: salt build-up in irrigated lands to levels that decrease crop yields.
Problems of Irrigation: Waterlogging results when excess irrigation water raises the water table & lowers crop productivity.
Types of erosion: • Sheet Erosion: Surface water runs down a slope and erodes layers of topsoil off; • Rill Erosion: fast-flowing water cuts small rivulets or channels in soil; • Gully Erosion: rivulets become bigger and join to form gullies
Soil conservation: reducing soil erosion & restoring soil fertility. • conservation–tillage farming minimizes soil disturbance. • use of special tillers which loosen subsurface soil without turning over top soil and residues; • no–till methods that inject seeds, fertilizers, & herbicides in unplowed soil; By maintaining a layer of crop residue on 30 % or more of the surface, reduces water erosion. Crop residue
Soil Conservation • terracing protects steep slopes; retains water for crops at each level and reduces erosion by controlling runoff; • contour farming follows natural land contours; each row of crops acts as a dam to slow water runoff down slopes
Soil Conservation • strip cropping maintains strips of different vegetation between crops; keeps soil covered, slows erosion, and some nitrogen-fixing plants ( such as legumes) can increase fertility.
Soil Conservation • alley cropping grows crops between rows of trees: The result is better erosion control, improved crop production, supplemental income, and habitat and travel corridors for wildlife.
Soil Conservation • wind breaks uses trees between fields to slow wind erosion • use of organic fertilizer (manure, "green manure" = plant matter, & compost);
Soil Conservation crop rotation : planting crops that restore nutrients; & decrease in use of inorganic fertilizers all help to restore fertility.
Soil Conservation • Good irrigation techniques can help slow wind and water erosion without waterlogging, causing excess runoff, or depleting water supplies • Grass in waterway slows water erosion.
Soil Erosion & Degradation
- Control measures of soil erosion slideshare
- Light induced degradation
- Estimation of degradation function
- Linear position invariant degradation
- How environmental degradation occurs
- Metabolismn
- Edman degradation
- Edman degradation
- Edman degradation steps
- Land degradation definition
- Importance of environmental degradation
- Tag degradation
- Edman degradation
- Purines
- Potential induced degradation
- Starch degradation
- Optimum notch filter in digital image processing
- Glycogen degradation
- Conclusion of environmental degradation
- Mechanical degradation
- Abnormal degradation of disaccharides
- Detachment transportation and deposition
- Soil erosion def
- Soil erosion
- South texas brush country weathering