The Pie chart below show the main reasons why agricultural land becomes Iess productivitive. The table shows how these causes affected regions of the world during the 1990s.

The graphs illustrate the proportion of activities that affect the growth of crops in both worldwide and three regions in the world.

Overall

,

it is clear that

the reason for degraded land is coming from over-grazing by cows which Oceania affected the most

while

Europe has land degradation more than other parts of the world. In a pie chart, over-grazing occurs from herbivores

for example

cows occupy 35%. Logging and over-agriculture almost have the same per cent which represents 30% and 28% respectively.

However

, the cause of other issues that affect the soil is only about 7%. Oceania's over-grazing registers 11.3% which is the highest of all regions but the earth in

this

part of the world is not affected by over-cultivation. Europe has total degraded soil higher than others which is nearly one-quarter of its land and deforestation is the main issue for their low-quality soil and it is mainly caused by overcrops.

Moreover

, North America's lands seem to have the least degradation, at 5%, and overgrowth of crops is their main problem same as in Europe.