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

The pie chart displays the

percentage

of the main cause of agricultural lands becoming unproductive. The table shows how

land

is affected by these reasons between the

three

continents. Looking at both graphs, there is less link between how the

percentage

of these causes worldwide affected the

three

areas. Having 23% of

land

degraded, Europe is at the top list, with its

three

different reasons ranging from 5.5 to 9.8 %.

Second,

in the list with a total

percentage

of less productive of 13% is mainly caused by overgrazing and deforestation. Surprisingly, none of the degraded

land

is caused by overcultivation.

While

overgrazing is the biggest factor, the data is only applicable to Oceania. In North America and Europe, the largest contributing factors are over-cultivation and deforestation with a

percentage

of 3.3 and 9.8% respectively. Being one-third of the reason

percentage

, the value of degraded

land

percentage

of the

three

regions does not correspond to the value of the worldwide.

Overall

,

although

for both figures, the causes may be the same, there is no matching relationship between the values of both graphs.