The pie charts 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

Given are the pie chart and the table which illustrate the factors of worldwide land degradation and the percentages of land degraded by different reasons in three regions: North America, Europe and Oceania during the 1990s.

Overall, the over-gazing by cattle was responsible for the worldwide land degradation. Comparing in three regions, Europe was the highest land degraded region, while Oceania was the lowest one in this record.

The first thing to mention is the main factor of worldwide land degradation in 1990s was over-gazing by animals. 35% of total less productivity of land was taken part in over-gazing, which was five times higher than other factors. The deforestation and over-cultivation were also major reasons of land degradation which contributed to 30% and 28%, respectively.

Secondly, the reasons of less productivity of agriculture land in three regions contributed to deforestation, over-gazing and over-cultivation. In Europe, the percentage of total land degraded was 23%, which was higher than Oceania and North America by 10% and 18%, respectively. In detail, the major causes were different in three regions as the deforestation was happened in Europe with 9.8%, the over-gazing was responsible in Oceania with 11.3% and the over-cultivation was the dominant reason in North America with 3.3%.

To sum up, two main reasons of using land was less productive in worldwide were over-grazing and deforestation, and the continent that had the most land degraded was Europe from deforestation.