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 the causes of global land deterioration. The table presents the percentage of land degraded by these reasons in three areas in the decade of 1990.
Overall, it is clear that the main reason caused less productive land is overgrazing. On the other hand, Europe area was affected seriously in term of total land degraded.
First of all, 35% of land deterioration was caused by overgrazing, which was 5% higher than the deforestation reason. Moreover, there is 28% of land degradation owing to overcultivation. However, other causes just accounted for below a tenth.
With regard to areas influenced by land degradation, Europe had the largest number, at 23% of total, compared with just 5% in North America. In particular, in total of land degraded, there were 9.8% due to deforestation and 7.7% from overcultivation presented in Europe were the highest figure among 3 regions. Meanwhile, the main reason in Oceania was overgrazing, at 11.3%.