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 chart reveals the percentage of three main causes having effects on land degradation while the table presents three areas suffering the land destruction over in 1990s. Overall, those causes averaged nearly same portion on decreasing function of farmland. On the other hand, Europe had the largest impacts among other regions.
There were three major sources of land degradation. Firstly, the most destroying factor was over-gazing that made for 35 per cent effects on the degradation. The following factor was deforestation that contributed 30 per cent destruction. However, over-cultivating causes 28 per cent effects on reducing the productivity of agricultural land.
Most degradation effects came from Europe which contributed 23 per cent from total land degraded including 9.8 per cent deforestation, 7.7 per cent over-cultivation, and 5.5 per cent over-gazing. On the other side, North America had the least effects on the degraded land consisted of only 5 per cent from total land degraded which averaged just under 1.5 per cent for each cause.