The pie chart illustrates the major causes why agricultural area becomes less efficient.The table presents how these reasons influenced three region of the world during the 1990.
Overall,it is apparently seen that dominating reason for agricultural land becoming less productive is over-grazing.Whereas the most of the land degradation is in Europe.
In terms of worldwide land deterioration,the dominating share is over-gazing,which accounts for 35%,followed by deforistation containing 30% in total.Marginally lower there is over-cultivation standing at 28%.Other factors contributing to land decay are at 7%.
Regarding the regions,deforestation is the least sourse of land degradation in North America(0,2%),followed by Oceania at 1,7%,as for Europe on the contrary deforistation is the main factor of land degradation.When it comes to over-cultivation,Europe making up to 7,7%,North America reaches up to 3,3%, and Oceania has no cases(0%).In contrast over-gazing is considerably enormous problem for Oceania occupying 11,3%,however North America and Europe have lesser percentages,1,5% and 5,5% respectively.In total most of the land degradation happens in Europe(32%),after that comes Oceania comprising 13% and North America has minor percentage between other continents constituting only 5%.