According to the WWF massive soil erosion Erosion eroding estimates Erosion eroding Farming: Soil erosion and degradation Erosion Erosion eroding According to the WWF arable land has been lost eroding wwf.panda.org Erosion eroding eroding Erosion "Soil erosion and degradation" wwf.panda.org eroding estimates Erosion arable land has been lost arable land has been lost