RDE726 Assessing the value of long-established permanent grassland for soil

The EIA regulations for uncultivated and seminatural grassland were enacted in England in the early 2000s with the aim of preventing cultivation of large areas of species rich, seminatural grasslands, or grasslands with important historic environment features, and they apply to any land management that increases the productivity of the land. Because cultivation typically leads to the rapid degradation of organic matter in the soil, and release of its nutrients, this is likely to temporarily increase productivity in almost all cases of old grassland being cultivated, but many grasslands were screened out due to their composition being more representative of more improved grassland.

Recently the regulations have been updated to include consideration of the impacts of cultivation on grassland soil carbon and soil biodiversity. Once established following cultivation, grassland soils accumulate carbon relatively rapidly and evenly over time, until they begin to reach an equilibrium point, estimated to occur around 80-100 years after establishment. When such soils are cultivated, they rapidly lose much of the accumulated soil carbon, returning them to a state more similar to an arable field. During grassland establishment, the soil communities will undergo a succession, changing from early communities that are similar to those found in arable soils (usually very species poor, low in biomass and dominated by ruderal species) to a more diverse range of more stress tolerant species.