It particularly affects heavily farmed land by reducing the soil’s ability to help crops grow because water, nutrients and rooting space are diminished. Estimates suggest that, within Europe, the current rate of soil loss from farmlands is 15 times greater than the estimated average background rate of soil erosion in prehistoric times.
Taking the current rate of soil erosion, the researchers were able to estimate future reductions in crop yield for one of the most commonly grown European wheats, using the PESERA1 (Pan European Soil Erosion Risk Assessment) model. The authors found that Mediterranean countries are most vulnerable to loss of agricultural soil, due to the local soil-type and climate. These countries are likely to suffer the largest relative reductions in yield with Greece likely to be the most badly affected, followed by Portugal, Italy, Spain and the south of France. However, their predictions suggest that when Europe is considered overall, the reductions in yield for wheat crops may not be as bad as previously thought. They suggest that modern innovations in farming, including the use of fertilisers, could be used to maintain crop yields despite the damaging effects of soil erosion.
The researchers warn that soil erosion should not be ignored, however. Loss of soil nutrients will gradually cause farmers to increase their use of chemicals, such as fertilisers and pesticides, and this will have an impact on local ecosystems. It will also reduce the sustainability of farming in the region.
There is a balance to be struck between the need to maintain food security and the environmentally damaging effects of both soil erosion and chemical fertiliser use. Not only do chemical fertilisers affect the local environment, but CO2 is released during their production which contributes to climate change. Furthermore, the model was built using current rates of erosion. Climate change is likely to increase erosion rates which will cause additional reductions in yield. The researchers suggest that the impacts of soil erosion on farming practices, ecosystems and society should be given as much precedence as productivity in any future planning.