A field parcel-oriented approach to evaluate the crop cover-management factor and time-distributed erosion risk in Europe

The crop cover-management(C-)factor in arable landscapes describes the soil erosion susceptibility associated with seasonally cultivated crops.Previous informatic and computational limitations have led many modelling studies to prescribe C-factor values and assume spatial and temporal stationarity.However,the multiple influencing factors ranging from parcel-scale crop cultivation and management to regional-scale rainfall regimes motivates new methods to capture this variation when identifying at-risk areas.Here,we define a multi-component method to derive the C-factor by associating time series of canopy and residue surface cover from Sentinel-2 and climate-specific rainfall erosivity with Integrated Administration and Control System(IACS)field parcel data from European Union member states.A scalable and standardised method is emphasised to increase the future interoperability and inter-comparability of soil erosion modelling studies deploying the C-factor.Additionally,field parcel simu-lation units with associated crop declarations provide a new reference scale to link predictions of soil erosion risk with specific management decisions and declarations by farmers.After implementing the method on a homogenised subsample of 8600 field parcels covering available IACS regions,several key findings are outlined:1)time series information provides new opportunities to predict the time-criticality of erosion in specific crop cultivations,2)the varying(a-)synchronicity between seasonal crop canopy cover and heavy rainstorms means that spatial variability is inherent within the C-factor across Europe,and 3)the addition of agricultural management practices(e.g.tillage practice de-scriptions)to open-access IACS repositories can facilitate more comprehensive evaluations of the C-factor and soil erosion risk.

Towards a better understanding of pathways of multiple co-occurring erosion processes on global cropland

Soil erosion is a complex process involving multiple natural and anthropic agents,causing the deterio-ration of multiple components comprising soil health.Here,we provide an estimate of the spatial pat-terns of cropland susceptibility to erosion by sheet and rill,gully,wind,tillage,and root crops harvesting and report the co-occurrence of these processes using a multi-model approach.In addition,to give a global overview of potential future changes,we identify the locations where these multiple concurrent soil erosion processes may be expected to intersect with projected dry/wet climate changes by 2070.Of a modelled 1.48 billion hectares(B ha)of global cropland,our results indicate that 0.56 B ha(-36%of the total area)are highly susceptible(classes 4 and 5)to a single erosion process,0.27 B ha(-18%of the total area)to two processes and 0.02 B ha(1.4%of the total area)to three or more processes.An estimated 0.82 B ha of croplands are susceptible to possible increases in water(0.68 B ha)and wind(0.14 B ha)erosion.We contend that the presented set of estimates represents a basis for enhancing our founda-tional knowledge on the geography of soil erosion at the global scale.The generated insight on multiple erosion processes can be a useful starting point for decision-makers working with ex-post and ex-ante policy evaluation of the UN Sustainable Development Goal 15(Life on Land)activities.Scientifically,this work provides the hitherto most comprehensive assessment of soil erosion risks at the global scale,based on state-of-the-art models.