caa a22 4500 463209222 CHVBK 20180405153135.0 cr unu---uuuuu 170326e20071101xx s 000 0 eng 10.1007/s10705-007-9116-4 doi (NATIONALLICENCE)springer-10.1007/s10705-007-9116-4 Temporal and spatial trends in soil organic carbon stocks following maize cultivation in semi-arid Tanzania, East Africa [Elektronische Daten] [Torben Birch-Thomsen, Bo Elberling, Bjarne Fog, Jakob Magid] Conversion of native ecosystems to agro-ecosystems influences the amount, quality and turnover of soil organic carbon (SOC). As most agro-ecosystems are not in a steady state in terms of the content of SOC, the time scale and feedback mechanisms of changes in SOC are highly relevant for predicting future soil fertility and potential rates of soil carbon losses or sequestration. This paper focuses on changes in land use linked to measured changes in the distribution of total stocks of SOC and the δ13C signature in the upper 0.5m of cultivated soils in the semi-arid parts of Tanzania. Based on documented land use changes since 1950s using remote sensing data, 12 sampling sites along two transects were selected to represent semi-natural/natural savannah and maize fields cultivated for up to five decades. Comparisons between sites representing a chronosequence of well-drained soils showed that soils cultivated the last 50years have in average less than 50% SOC compared to soils which have never been cultivated. Variations between sites were significant and a reduction in SOC could not be established at sites near present or former villages which have received substantial manure despite a long cultivation history or along a chronosequence representing wetter and more fine-grained soils. Spatial variations in land use changes were parameterized based on remote sensing data and successfully validated against sampling sites. Site-specific rates of soil element loss following cultivation were extrapolated to the study area and uncertainties related to scaling up were discussed. Springer Science+Business Media B.V., 2007 Soil organic carbon nationallicence Tanzania nationallicence Land use changes nationallicence Agriculture nationallicence Birch-Thomsen Torben Department of Geography and Geology, University of Copenhagen, Øster Voldgade 10, 1350, Copenhagen K, Denmark aut Elberling Bo Department of Geography and Geology, University of Copenhagen, Øster Voldgade 10, 1350, Copenhagen K, Denmark aut Fog Bjarne Department of Geography and Geology, University of Copenhagen, Øster Voldgade 10, 1350, Copenhagen K, Denmark aut Magid Jakob Department of Agricultural Sciences, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark aut Nutrient Cycling in Agroecosystems Springer Netherlands 79/3(2007-11-01), 291-302 1385-1314 79:3<291 2007 79 10705 https://doi.org/10.1007/s10705-007-9116-4 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10705-007-9116-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Birch-Thomsen Torben Department of Geography and Geology, University of Copenhagen, Øster Voldgade 10, 1350, Copenhagen K, Denmark aut NATIONALLICENCE 700 1- Elberling Bo Department of Geography and Geology, University of Copenhagen, Øster Voldgade 10, 1350, Copenhagen K, Denmark aut NATIONALLICENCE 700 1- Fog Bjarne Department of Geography and Geology, University of Copenhagen, Øster Voldgade 10, 1350, Copenhagen K, Denmark aut NATIONALLICENCE 700 1- Magid Jakob Department of Agricultural Sciences, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark aut NATIONALLICENCE 773 0- Nutrient Cycling in Agroecosystems Springer Netherlands 79/3(2007-11-01), 291-302 1385-1314 79:3<291 2007 79 10705 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer