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SOIL DEGRADATION AND SOIL DEGRADATION AND DESERTIFICATION-A ChallengeDESERTIFICATION-A Challenge
By:ASHISH(2011A22BIV)By:ASHISH(2011A22BIV)
SOIL DEGRADATIONSOIL DEGRADATION
• Soil degradation is the decline in soil quality caused by its improper use, usually for agricultural, pastural, industrial or urban purposes.
• The Decline in quantity and quality of soil It includes Erosion by wind and water Biological degradation (loss of humus) Physical degradation (loss of structure, permeability, compaction) Chemical degradation (reduced fertility, salinisation , changing pH, toxicity)
SOIL DEGRADATIONSOIL DEGRADATION
DESERTIFICATION
If Degradation is so severe that land becomes unusable it is termed desertification
DESERTIFICATIONDESERTIFICATION• Desertification is a process of turning the
productive land into desert.
• A definition of desertification should recognize that it is a land degradation process that involves a continuum of change, from slight to very severe degradation of the plant and soil resource, and is due to man's activities.
• Desertification is also a situation on the desert expansion. That means desert is continuously expanding to the surrounding area.
Causes on desertificationCauses on desertificationdesertification
High pop. Poor / poverty
Climatic change
Over cropping
deforestation
Over grazing
Global warming
Low Rainfall
↓ Soil fertility ,↓ soil degradation &↓ Soil aridity
Human factors
+Impropriate irrigation
-salinization
CauseCauseHuman factors:High population
Deforestation--- Demand∵ more land and timber for cropping & building, cutting down to tree extensively.
Over cropping—- demand∵ for food crops↑ & the cash crops demanded ↑, ↑shifting cultivation, ↓soil fertility, secondary growth
CauseCauseImpropriate irrigation:
infiltration >E underground water table rises salinization
Climatic change
Global warmingCO2↑, T ↑, ice cap melt, flooding in coastal area , ↓ rainfall, drought , veg. die
Less rainfallDrought , veg. die.
“If the climatic factors are said to be the main causes of desertification ,then human activities are going to intensify it.”
Effects on desertificationEffects on desertificationdesertificationdesertification
Atmosphere
-local climate
↓R”
drought
-macro climate
global warming
Hydrosphere
-water cycle
breaks down
Lithosphere
-loss of arable
salinization
-land intensify the
soil erosion
Biosphere
-extinction of plants & animals
-↓biodiversity
Upset the balance of ecosystem
EffectsEffects
EffectsEffectsLithosphere
1)loss of arable land
soil texture change to sandy ↓cohesive power (cannot hold water) not suitable for veg growth
2)intensify the soil erosion
1.↑ deforestationno root to bind the soil
↑ soil erosion↑ silting
EffectsEffectsHydrosphere 1)Water cycle breaks down ↓∵ Rainfall & ↑ evaporation( no shelter)∵ rivers and wells dried up
Biosphere 1)lower the bio-diversity ↓R” & unevenly dis.+deforestation scattered veg. (veg. Is shorter, few species, less luxuriant)extinction
EffectsEffects
Others 1)lower the income
Rainfall ↓ crops productivity ↓,
2)use a large amt of capital for soil
protection & recovery
How to solve???How to solve???
1.Control the pop. growth / natural increase by using family planning, in order to decrease the land use capacity
2.The number of grazing and the rate of cultivation should not over the carrying capacity of land
How to solve???How to solve???
3. Improve i)farming & ii)grazing methods, in other to reduce soil erosion and
salinization
i) suitable timing and amount to carry out irrigation
plant the halophytes (which can adapt salty &
droughted soil) e.g, Chenopodiaceae
ii)sufficient fallowing period
How to solve???How to solve???
4.Legislation: band the deforestation and over grazing, etc. , in order to balance the ecosystem of desert.
5.afforestation i.e. plant the wind break trees & drought resistant plants
6.stone lines
7. Building reservoir and canal , (e.g, The Indira Gandhi Canal)
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