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)