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15th SEPTEMBER2013

SOIL EROSION AND ITS AFFECTS ONSUSTAINABLE AGRICULTURE

PRESENTED BY:-Kaushal. V. Gadariya (097)Dave Dhruv .D (094)Sharma Gautam. B (116)3rd semesterPolytechnic in agriculture engineering, Anand agriculture university,Muvaliya farm, Dahod-389151

-Erosion.CONTENTS-Mechanics of erosion.-Black Sunday-Types of Erosion- Agents of Erosion. -Classification of Erosion. -Water erosion and its types. -Factors affecting water Erosion.-Wind erosion.- Methods of Soil conservation.-How to conserve soil ?

The erosion termed indicates the meaning of soil remove from one place and depositing them to some another place.Removal of soil from its original positionIt is the process of detachment, transportation & deposition of soil materials from one place to another by erosive agents

Every year in India 16.5 tons/ha/year soil erosion is occur by agents of erosion.

WHAT IS EROSION ?Mechanics of erosionA) Detachment.

Transportation.

C) Deposition.

Types of ErosionIn general there are two types of soil erosion.

Geological Erosion:-It is caused by nature.

Accelerated Erosion:- It is caused by human activities.

Agents of Erosion1. Wind. - ERODIBILITY 2. Water. - EROSIVITY

3. Temperature.

4. Biological Factors.

Classification of Erosion Depending upon the erosion causing factors

A) Wind Erosion.

B) Water Erosion.

WATER EROSION

Types of water erosion:-1.Rain splash erosion.2.Sheet erosion.3.Rill erosion.4.Gully erosion.5.Stream bank erosion. Other forms of erosion:-1.Glasical erosion.2.Snow erosion.3.Organic erosion.4.Underground Erosion.5.River erosion. Rain Splash Erosion: Rain splash erosion is caused by the impact of water striking the surface of soil.It takes place in two steps.1. As precipitation fills the pore spaces, loosening & driving soil particles apart.2. Impact of subsequent rain drops hitting the surface, transporting particles to other area.

Sometimes water flows as a sheet over large areas down a slope. In such cases the top soil is washed away. This is known as sheet erosion. Sheet Erosion

Rill Erosion. It is caused by water concentrating into innumerable, closely spaced small channels. Left unchecked, rills can cut vertically & horizontally and when joined form gullies.

Gullies: The running water cuts through the clayey soils and makes deep channels as gullies.

Gully erosion

Stream Erosion.When flow in gullies become permanent, it is called a stream which may be permanent or seasonal is called as stream erosion.

Factors affecting water ErosionA) Climate. 1. Precipitation. 2. Temperature. 3. Wind. 4. Humidity. 5. Solar radiation.B) Soil. 1. Physical properties of soil. 2. Vegetation cover. 3. Organic matter contents in soil. 4. Moisture contents of soil. 5. Soil density.

It is the process in which removal of soil particles moves one place to another place by wind in known as wind erosion.

Wind erosion

Black Sunday

April 14th,1935 black Sunday was the worst blizzard of the dust storm with high speeds which caused the most extensive damage. It occurs in United states in Boise city at 5:15 PM. It is estimated to have displaced 300 thousand tons of topsoil from the Prairie area in the US.

Methods of Soil conservationii. Terrace Farming: Steps can be cut out on the slopes making terraces. Terrace cultivation restricts erosion. Western and central Himalayas have well developed terrace farming.

Contour Ploughing: Ploughing along the contour lines can decelerate the flow of water down the slopes. It used in tea cultivation.

iii. Strip Farming: Large fields can be divided into strips. Strips of grass are left to grow between the crops. This breaks up the force of the wind. iv. Shelter Belts: Planting lines of trees to create shelter also works in a similar way. Rows of such trees are called shelter belts. These shelter belts have contributed significantly to the stabilization of sand dunes and in stabilizing the desert in western India.

How to conserve soil ?Conservation of soil can be done several ways. Planting trees helps. Trees prevent erosion both with their roots and by blocking wind. Terracing is another good way to conserve soil. Terracing is leveled sections used for hilly farm lands. Tilling and plowing helps prepare soil for plants to grow, but it is promotes erosion, so finding ways to limit how much you till and plow will help.

References - SOIL AND WATER CONSERVATION ENGINEERING BOOK BY . R.SURESH - INTERNET