摘要：Abstract. Arable soils are critical resources that support multiple ecosystemservices. They are frequently threatened, however, by accelerated erosion.Subsequently, policy to ensure their long-term security is an urgentsocietal priority. Although their long-term security relies upon a balance betweenthe rates of soil loss and formation, there have been few investigations ofthe formation rates of soils supporting arable agriculture. This paperaddresses this knowledge gap by presenting the firstisotopically constrained soil formation rates for an arable(Nottinghamshire, UK) and coniferous woodland hillslope (Shropshire, UK).Rates ranged from 0.026 to 0.096 mm yr−1 across thetwo sites. These rates fall within the range of previously published ratesfor soils in temperate climates and on sandstone lithologies butsignificantly differed from those measured in the only other UK-based study.We suggest this is due to the parent material at our sites being moresusceptible to weathering. Furthermore, soil formation rates were found tobe greatest for aeolian-derived sandstone when compared withfluvially derived lithology raising questions about the extent to which thepetrographic composition of the parent material governs rates of soilformation. On the hillslope currently supporting arable agriculture, weutilized cosmogenically derived rates of soil formation and erosion in afirst-order lifespan model and found, in a worst-case scenario, that thebackslope A horizon could be eroded in 138 years with bedrock exposureoccurring in 212 years under the current management regime. These findingsrepresent the first quantitative estimate of cultivated soil lifespans in the UK.
