The pie chart below shows the main reasons why agricultural land becomes less productive. The table shows how these causes affected three regions of the world during the 1990s.

The pie chart demonstrates why causes agricultural

land

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produces less than before survey years. The table illustrates how

deforestation

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, over-cultivation, and over-grazing affected three regions (North

America

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,

Europe

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, and

Oceania

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) in the 1990s.

Overall

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, Over-grazing is the main reason which makes

land

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degrade

while

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other reasons only need to take less responsibility for

this

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.

On the other hand

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, in

Europe

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, 23% of

land

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faces the problem of degradation but only 5% of

land

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in North

America

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has

this

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environmental problem. To face the question of which

land

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over the world is degraded, we can see over-grazing takes the biggest proportion, 35%,

whereas

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deforestation

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and over-cultivation only maintain 30 % and 28%. Another reason which causes

land

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degradation only takes 7%. The

land

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of

Europe

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has 23% faced

land

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degradation

while

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the

land

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of North

America

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and

Oceania

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only takes 5% and 13% respectively.

Deforestation

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is caused 9.8% of the

land

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in

Europe

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to be less productive. In contrast, only 0.2% of

deforestation

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happened in North

America

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while

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there is only 1.7% in

Oceania

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. There is 7.7% of

Europe

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's

land

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degraded by over-cultivation

while

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0% and 3.3% in

Oceania

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and North

America

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. 11.3% of

Oceania

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's

land

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faces the issue of over-grazing

whereas

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North

America

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and

Oceania

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have only 5.5% and 1.5% of

land

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become weaker and weaker respectively.