over-grazing and deforestation of agricultural land
The circle graph illustrates the explanation about the low productivity of agriculture land. Meanwhile, the table indicates how these causes impacted three regions of the world during the 1990s.
Overall, over-grazing and deforestation were the main reasons why argriculture land becomes less productive worldwide. Europe seems to be the country that had the highest total land degraded.
The decrease of land for farming was from many factors. According to the pie chart, over-grazing accounted for 35 percent - more than one third of the degradation. Next, the highest percent after over-grazing was 30 percent for deforestation. People destroyed land in order to build houses, take wood and so on. Over-cultivation was also one of the reasons why the reducing happened, taking 28 percent. Many other factors that made the decrease of argriculture land accounted for 7 percents - less than over-grazing, deforestation and over-cultivation.
Regarding to the table, Europe affected most by the degradation of land. It accounted for nearly a quarter of the total land in this country with 9.8% for deforestation. However, in Oceania, over-grazing was the highest cause - 11.3% compared to other factors. The total land degraded in North America is little than other two countries, just 5 percent with over-cultivation is the highest reason - accounting for 3.3% of all.