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 explains the four most common reasons behind the low productivity of agricultural land and the table chart reveals the impact of these activities on three Nations particularly North America, Europe and Oceania.

Coming back to details, over one-third of worldwide land is degraded because of overgrazing; it is followed by 30% damage caused by deforestation globally. Over cultivation is also a significant cause of degradation of global land which affects 28% land However, the land being affected by other reasons is negligible.

Moving further to areas affected by degradation in 1990s, Europe was the one region which had maximum infertile land and the most common reason for this was deforestation (9.8%) followed by over-cultivation (7.7%) and overgrazing (5.5%). Overgrazing and deforestation caused 11.3% and 1.7% damage to Oceania out of 13 % of total land degraded and it is very interesting to notice that over cultivation had no impact on this area. In the end, only 5% of the land was graded in North America from over-cultivation, overgrazing and trees cutting accordingly.