Soil organic matter and erosion
In 2013 we compared soil organic matter in ten year-old dry grassland and neighbouring arable land. The results were:
Dry grassland: 3.6%
Arable land: 2.7%
It is likely that this rate of organic matter accumulation will slow down.
The dry grasslands are mostly either on very sandy soils that are prone to wind erosion or on the slopes of the chalk scarp which are prone to water erosion. In both cases, the establishment of grassland prevents soil erosion.