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

illustrates some principal causes that contribute to the degradation of the

land

and the table demonstrates the negative effects on the three continents during the 1990s. All units were shown in percentage.

Overall

, the majority of

land

in the pie

chart

was degraded by over-grazing and

deforestation

. In the table, the highest proportion of

land

being destroyed was in Europe and the opposite was true for North America. Looking at the pie

chart

, the main reason for the degradation of the

land

was over-grazing, which was the biggest number in the

chart

, 35%.

Besides

that, a third of less productive agricultural

land

was the consequence of

deforestation

, which was higher than over-cultivation, 29%. The final figure was other factors, the lowest part in the

chart

, 7% of all. Concerning the table, Europe had the highest proportion of

land

degraded, 23% which contained the majority of

deforestation

, 9%, 7.7% of over-cultivation and 5.5% in over-grazing fields. Looking at Oceania, it had the majority of effects caused by over-grazing, 13%, and just owned 1.7% of

deforestation

. The region had the lowest of

land

degraded, 5%, North America was affected primarily by over-cultivation, accounting for 3.3%,

besides

that it had 0.2%

deforestation

and 1.5 of over-grazing too.