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

produces less than before survey years. The table illustrates how

deforestation

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

America

,

Europe

, and

Oceania

) in the 1990s.

Overall

, Over-grazing is the main reason which makes

land

degrade

while

other reasons only need to take less responsibility for

this

.

On the other hand

, in

Europe

, 23% of

land

faces the problem of degradation but only 5% of

land

in North

America

has

this

environmental problem. To face the question of which

land

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

whereas

deforestation

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

land

degradation only takes 7%. The

land

of

Europe

has 23% faced

land

degradation

while

the

land

of North

America

and

Oceania

only takes 5% and 13% respectively.

Deforestation

is caused 9.8% of the

land

in

Europe

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

deforestation

happened in North

America

while

there is only 1.7% in

Oceania

. There is 7.7% of

Europe

's

land

degraded by over-cultivation

while

0% and 3.3% in

Oceania

and North

America

. 11.3% of

Oceania

's

land

faces the issue of over-grazing

whereas

North

America

and

Oceania

have only 5.5% and 1.5% of

land

become weaker and weaker respectively.