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

The diagram illustrates how agricultural land became less productive, and the table compares how these causes affected North America, Europe, and Oceania in 1990.

Overall, over-grazing had the largest share in this era which can be seen as the main key of land degradation. Moreover, Europe was reported as having the highest percentage of land degradation.

Over-grazing was responsible for the highest share at 35%, followed by deforestation as the second highest share at 30%. Furthermore, over-cultivation accounted for 28%. Other reasons were only had 7%.

On the table, Europe ranked first in deforestation (9.8%) and over cultivation (7.7%). While over-grazing in Oceania had the highest proportion (11.3%), over-cultivation was not the case in this region. However, deforestation was at 1.7%. Besides, it is known that North America had the lowest proportion among all causes (0.2%, 3.3%, 1.5% respectively). Finally, over-grazing in Europe accounted for 5.5%, which was the weakest percentage in this country.