SOIL DEGREDATIONBy: Eric Fabick

DEFINING DEGRADATION

Degradation is a process in which soil is loosened up through a variety of activities. Then through the process of erosion (both wind and water) it is carried away.

WORLD MAP SHOWING SOIL DEGRADATION

FOUR WAYS IN WHICH HUMANS CONTRIBUTE TO SOIL DEGRADATION

Humans contribute in four different ways

1. Over cultivation – Farmers continually reuse the same land over and over without ever contributing any sort of plant matter back. This loosens soil particles making then susceptible to erosional forces.

Over grazing – Many grazing lands are open grasslands which lack a lot of rainfall. By allowing livestock to over graze the land becomes susceptible to erosional forces.

LIVESTOCK GRAZING

Poor irrigation practices – By adding water so areas where it is very dry year round, the salt level in the soil is increased which effectively loosens it allowing it so be susceptible to erosional forces.

Deforestation – This is when trees are cut down and not replanted so the roots are no longer present to hold in the soil so the soil becomes susceptible to erosional forces.

DEFINE DESERTIFICATION

Desertification is essentially a very severe form of soil degradation. It threatens an estimated 1/5th of earths land.

EXPLAIN HOW WIND AND WATER CONTRIBUTE TO SOIL EROSION

Once the top soil is loosened by soil degradation, water and wind is free to basically take the soil wherever it pleases. This basically means that wind and water are the main forms of soil erosion.

FOUR WAYS TO PREVENT WIND EROSION

Shelter Belts – Shelter belts are trees planted in a line to aid in air resistance.

THIS IS A SHELTER BELT

Planting Crops that grow at different times of the year aids in causing wind resistance. By doing this the field never becomes bare.

Farmers never plough the fields in the direction of the wind. These furrows created by ploughing acts like a wind tunnel increasing wind speed. They usually plough fields in the evening or morning because that’s when wind speeds are the slowest.

STUBBLE MULCHING

When crops are harvested the stubble is left in the ground to defends the soil. This creates increased wind drag which aids in protecting soil.

Ways to combat water erosion

1. Contour Ploughing on slops creates furrows that prevents water from successfully flowing downhill.

Planting strips of grass between crops on a hill helps anchor the soil in place.

Terracing creates flat areas or varying heights in a stair like shape. This prevents water erosion because all of the eroded soil gets washed down into the next tier.

THE TOP FOUR SOIL EROSION HOTSPOTS OF THE WORLD

1. Plains and prairies of North America Immense pressure to grow more and

more types of grains at a rapid pace to feed the population quickly wore out the soil. The constant year round winds and the convectional rainfall causes the soil to be eroded and it becomes more and more of a problem by the year.

Northeast Brazil Brazil is an area already dry from years

of drought. They do not have the means to use the soil for farming. There is little to no protection to prevent erosion.

The north fringe of the Sahara desert The massive expansive of desert

covering nearly 10,00,00 kilometers due to the lack of vegetation preventing it from being eroded by the wind,. This causes the desert to slowly advance to the north.

Southern fringe lands of the Sahara Desert This land has one of the worst situations. It

is afflicted by little moisture, overgrazing, deforestation, the land has been over used for farming. The land is constantly the target of dust storms. They have to continue using the already poor quality land to grow crops required for their survival. The land is also subject to the constantly advancing Sahara which threatens to totally consume the area.