Branch : Mechanical Engineering�Semester : 3rd

Subject : Environmental Studies

Chapter : 02

Topic : Natural resources

Sub Title : Land Resources

Faculty : Er. Suchismita Parida

Mayurbhanj School Of Engineering, Baripada

Land Resources

LAND RESOURCES

The Importance of Land

• The human civilization has thrived on land.

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• Land is used for agriculture.

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• Land contains huge amount of mineral deposits.

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• It also contains water in the form of underground water.

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• Most of the animals find their habitat on land.

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• Land directly or indirectly provides all the resources required to fulfil the basic needs of humans: food, cloth, and shelter.

SOIL PROFILE

• Soil profile is a vertical cross section from surface down to the parent materials. A well- developed soil profile shows distinct horizons.

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• The three major horizons are A, B, and C horizons. Horizons are sometimes also called zones.

• The soil profile is important tool for nutrient management and soil fertility.
• Decomposition of weathers and organic matter, profile of the soil changes.
• The soil profile is made of distinct layers , known as horizons.
• Five most common horizons are collectively known as master horizons.
• Study of soil profile is essential for proposed the soil structure and for technical descriptions.

Horizons in Soil profile

FUNCTIONS OF SOIL

^ Role in nutrient cycles

^In agriculture

^ Regulate the water

^ Regulate the emissions of gases

^ Degrade pollutants and filter ground water

^ Producing clay

^ Provide the structural material as brick, cement etc.

^ Sequester carbon as organic matter.

LAND DEGRADATION

The fertility of land supports the growth and productivity of natural vegetation and agricultural crops. A number of natural and man-made factors lower the quality of land. This is commonly referred to as land degradation.

CAUSES OF LAND DEGRADATION

Natural factors

^Heavy rains

^High speed wind and storms

^Natural disasters like earthquakes ,floods, prolonged drought, etc.

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Anthropogenic factors

^Mining.

^Urbanization

^The indiscriminate and uncontrolled removal of trees

^Excess use of fertilizers

^Industrial discharges

^Overgrazing, soil erosion, etc..

SOIL EROSION

Soil erosion is removal of top soil from its resting place by various physical agencies like wind and water. It can be defined as “the detachment and transport of the fertile layer of soil by water or air.” It is also known as the creeping death of land.

The detachment and transportation of the fertile layer of soil by water or air.

CAUSES OF SOIL EROSION

• Large-scale deforestation for meeting commercial as well as day-to-day needs

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• Heavy floods in rivers

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• Overgrazing by cattle

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• Dry violent winds

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• Improper agricultural techniques

EFFECTS OF SOIL EROSION

• Desertification of land

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• Decrease in productivity of land

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• Reduction in the agricultural land at the banks of rivers

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• Deposition of soil in river beds and canals causing diversion of their natural flow and hence leading to disasters

METHODS OF CONTROLLING SOIL EROSION

• Reduced tillage

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• Contour cultivation

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• Strip cropping

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• Terracing

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• A forestation on barren land

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• Control of overgrazing

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• Construction of small check dams

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• Promotion of equitable use of water resources

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• Prevention of excavation of rocks

METHODS TO CONTROL SOIL EROSION

Strip cropping

Contour banding

Terracing

Afforestation

Construction of small check dams

DESERTIFICATION

Causes of Desertification

Natural Factors

Very low rainfall High salinity of soils Excessive evaporation

Vast difference in diurnal temperature extremes

Anthropogenic Factors

Overgrazing Over irrigation

Excessive ploughing Excessive use of fertilizers Continuous cutting of trees

Conversion of fertile land into an infertile desert land is called desertification.

EFFECTS OF DESERTIFICATION

• Poor soil quality

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• Rapid soil erosion

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• Unfavorable climate

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• Huge economic losses

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• Low water table, salty and hard water

CONTROL OF DESERTIFICATION

• Promoting large-scale plantation of trees

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• Changing agricultural practices and promoting dry land farming

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• Development of pasture lands (suitable for Grazing) and control of overgrazing

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• Promoting equitable use of water resources

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• Development of water catchment areas

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The desertification is increasing significantly in Bhuj in northern Gujarat due to over usages of ground water for last 20 years.

Water tables going down by 3m/year.

Thank You