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5.3: Soil degradation and conservation - Coggle Diagram
5.3: Soil degradation and conservation
Development of fertile soils
Fertile soils is developed over a long period of time
Amount of time required for the formation of soils differ from soil to soil, coarse sandstone developed more quickly compared to granites
Deep soils does not mean mature soils, and vice versa
Animals activity
have effects on soils
Earthworms ingest soils and passed it to the surface
Bacteria fix atmospheric nitrogen into usable form for plants
Decomposers break down litter, releasing nutrients into the soils
Animals burrow help to aerate the soils
Human activity such as liming, fertilizer application, and deforestation also affects the soils fertility
Fertile soils contain a community of organisms that work to maintain functioning nutrient cycles and are resistant to soil erosion
Reduced soil fertility
Deforestation
The removal of some or all cover of trees
More trees removed = less interception = more soil compaction by raindrop
Potential for soil erosion increases with rainfall, hence why the deforestation of rainforests is serious issue
Intensive
grazing
Impacts on vegetation cover:
More intense grazing = more vegetation cover removed
Large herds may destroy vegetation covers by trampling
Reduce interception, increase raindrop impact, increase soil erosion
Grazers may compact the soil, making it less permeable and increase potential for soil erosion. In severe cases, can cause desertification
Urbanization
Rate of soil erosion is greatest during urbanization
This is because urbanization requires the removal of vegetation for construction, and machinery compacts the soils
Water cannot permeate, hence it erode the fertile topsoil
Irrigation
Leads to increased salt concentration in the soil
Occurs because the groundwater evaporated, leaving behind soluble salt ie. salinization
Monoculture
Can lead to soil exhaustion, where the same type of minerals is required by the plants, hence over time the minerals depleted
Commercialized food
production systems
The production of mass-produced, standardized food has led to soil quality deteriorated due to soil exhaustion, erosion and toxification. There has been greater use of pesticides and herbicide
Soil conservation methods
Revegetation
Deliberate planting and suppression of grazing and such to allow regeneration
Stop bank erosion
make concrete banks
Stop gulley
enlargement
Planting of trailing plants and constructing dams
Crop management
Maintaining vegetation cover at critical times of the year, do plant rotation, and plants cover crops
Slope run-off
control
Terracing
Deep tillage and apply humus
Do contour ploughing
Preservation of vegetation strips to limit field width
Prevention of soils erosion from point sources
Covering banks with vegetation
Channels drainage water to non-susceptible areas
Suppression of wind erosion
Preserve soils moisture
Increase the surface roughness by ploughing up clods or by planting windbreaks
Avoid farming on marginal lands, which are land that is too dry or infertile