title: Potential of temperate agricultural soils for carbon sequestration: A meta-analysis of land-use effects.
abstract: Restoring depleted soil organic carbon (SOC) stocks of arable land to remove carbon from the atmosphere and offset fossil fuel emissions is a promising strategy for the mitigation of climate change. In agroecosystems conservational tillage practices and the abandonment of formerly plowed fields (ex-arable land) are shown to have the highest potential to sequester SOC. Nevertheless reported sequestration rates vary and the effects of environmental site conditions remain poorly understood. Our results are based on a meta-analysis of 273 paired SOC estimates from 65 publications which included only mineral soils from the temperate zone. SOC stocks of ex-arable grasslands with an average of 14years since abandonment were 18% larger compared to the SOC of arable land. Likewise, SOC stocks of never-plowed grassland plots were 11% larger than the SOC stocks of abandoned fields. The average sequestration rate was 0.72t Cha(-1)yr(-1). Semi-arid and sub-humid climate as well as low initial SOC stocks positively affected proportional SOC gains suggesting that the recovery of carbon stocks is not limited by low primary production. Therefore, the northward shift of cultivation areas in the temperate zone will lead to the abandonment of soils with high SOC recovery potential. However, if native soils are opened up elsewhere to compensate for yield losses due to abandonment the surplus of SOC in ex-arable land can easily be overcompensated by cultivation losses.
authors.affiliation: Faculty of Agricultural Sciences and Landscape Architecture, Osnabrück University of Applied Sciences, Oldenburger Landstraße 24, 49090 Osnabrück, Germany. Electronic address: immokaempf@uni-muenster.de.
authors.forename: Immo
authors.initials: I
authors.lastname: Kämpf
authors.affiliation: Institute of Landscape Ecology, University of Münster, Heisenbergstr. 2, 48149 Münster, Germany.
authors.forename: Norbert
authors.initials: N
authors.lastname: Hölzel
authors.affiliation: Institute of Geography, University of Osnabrück, Seminarstr 19 A-B, 49074 Osnabrück, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Störrle
authors.affiliation: Institute of Geography, University of Osnabrück, Seminarstr 19 A-B, 49074 Osnabrück, Germany.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Broll
authors.affiliation: Faculty of Agricultural Sciences and Landscape Architecture, Osnabrück University of Applied Sciences, Oldenburger Landstraße 24, 49090 Osnabrück, Germany.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Kiehl
keywords: Agricultural abandonment; Carbon sequestration; Ex-arable; Grassland restoration; No-till farming; SOC