title: Modelling the impact of agricultural management on soil carbon stocks at the regional scale: the role of lateral fluxes.
abstract: Agricultural management has received increased attention over the last decades due to its central role in carbon (C) sequestration and greenhouse gas mitigation. Yet, regardless of the large body of literature on the effects of soil erosion by tillage and water on soil organic carbon (SOC) stocks in agricultural landscapes, the significance of soil redistribution for the overall C budget and the C sequestration potential of land management options remains poorly quantified. In this study, we explore the role of lateral SOC fluxes in regional scale modelling of SOC stocks under three different agricultural management practices in central Belgium: conventional tillage (CT), reduced tillage (RT) and reduced tillage with additional carbon input (RT+i). We assessed each management scenario twice: using a conventional approach that did not account for lateral fluxes and an alternative approach that included soil erosion-induced lateral SOC fluxes. The results show that accounting for lateral fluxes increased C sequestration rates by 2.7, 2.5 and 1.5 g C m(-2)  yr(-1) for CT, RT and RT+i, respectively, relative to the conventional approach. Soil redistribution also led to a reduction of SOC concentration in the plough layer and increased the spatial variability of SOC stocks, suggesting that C sequestration studies relying on changes in the plough layer may underestimate the soil's C sequestration potential due to the effects of soil erosion. Additionally, lateral C export from cropland was in the same of order of magnitude as C sequestration; hence, the fate of C exported from cropland into other land uses is crucial to determine the ultimate impact of management and erosion on the landscape C balance. Consequently, soil management strategies targeting C sequestration will be most effective when accompanied by measures that reduce soil erosion given that erosion loss can balance potential C uptake, particularly in sloping areas.
authors: Earth and Life Institute - TECLIM, Université catholique de Louvain, Place Louis Pasteur 3, 1348, Louvain-la-Neuve, Belgium.
authors: Elisabet
authors: E
authors: Nadeu
authors: Flemish Institute for Technological Research - VITO, Boeretang 200, 2400, Mol, Belgium.
authors: Anne
authors: A
authors: Gobin
authors: Institut für Geographie, Universität Augsburg, Alter Postweg 118, 86159, Augsburg, Germany.
authors: Peter
authors: P
authors: Fiener
authors: Earth and Life Institute - TECLIM, Université catholique de Louvain, Place Louis Pasteur 3, 1348, Louvain-la-Neuve, Belgium.
authors: Bas
authors: B
authors: van Wesemael
authors: Earth and Life Institute - TECLIM, Université catholique de Louvain, Place Louis Pasteur 3, 1348, Louvain-la-Neuve, Belgium.
authors: Kristof
authors: K
authors: van Oost
mesh_terms: D000383:Agriculture / Q000379:methods*; D001530:Belgium; D002244:Carbon / Q000032:analysis*; D057965:Carbon Sequestration; D008962:Models, Theoretical; D012987:Soil / Q000737:chemistry*
chemical_list: D012987:Soil; D002244:Carbon
keywords: agricultural management; carbon sequestration; soil erosion; soil organic matter; spatial modelling