Articles | Volume 10, issue 1
https://doi.org/10.5194/soil-10-275-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/soil-10-275-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
SOIL Letters
| Highlight paper
| 
15 Apr 2024
SOIL Letters | Highlight paper |
| 15 Apr 2024
| 15 Apr 2024
The six rights of how and when to test for soil C saturation
Department of Environmental Systems Science, ETH Zurich, Zurich, 8092, Switzerland
Sebastian Doetterl
Department of Environmental Systems Science, ETH Zurich, Zurich, 8092, Switzerland
Moritz Laub
Department of Environmental Systems Science, ETH Zurich, Zurich, 8092, Switzerland
Claude R. Müller
Department of Environmental Systems Science, ETH Zurich, Zurich, 8092, Switzerland
Marijn Van de Broek
Department of Environmental Systems Science, ETH Zurich, Zurich, 8092, Switzerland
Related authors
Vira Leng, Rémi Cardinael, Florent Tivet, Vang Seng, Phearum Mark, Pascal Lienhard, Titouan Filloux, Johan Six, Lyda Hok, Stéphane Boulakia, Clever Briedis, João Carlos de Moraes Sá, and Laurent Thuriès
EGUsphere, https://doi.org/10.5194/egusphere-2024-541, https://doi.org/10.5194/egusphere-2024-541, 2024
Short summary
Short summary
We assessed the long-term impacts of no-till cropping systems on soil organic carbon and nitrogen dynamics down to 1 m depth under the annual upland crop productions (cassava, maize, and soybean) in the tropical climate of Cambodia. We showed that no-till systems combined with rotations and cover crops could store large amounts of carbon in top and subsoil, in both the mineral organic-matter and particulate organic matter fractions. It also questions nitrogen management in these systems.
Armwell Shumba, Regis Chikowo, Christian Thierfelder, Marc Corbeels, Johan Six, and Rémi Cardinael
SOIL, 10, 151–165, https://doi.org/10.5194/soil-10-151-2024, https://doi.org/10.5194/soil-10-151-2024, 2024
Short summary
Short summary
Conservation agriculture (CA), combining reduced or no tillage, permanent soil cover, and improved rotations, is often promoted as a climate-smart practice. However, our knowledge of the impact of CA on top- and subsoil soil organic carbon (SOC) stocks in the low-input cropping systems of sub-Saharan Africa is rather limited. Using two long-term experimental sites with different soil types, we found that mulch could increase top SOC stocks, but no tillage alone had a slightly negative impact.
Mosisa Tujuba Wakjira, Nadav Peleg, Johan Six, and Peter Molnar
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2024-37, https://doi.org/10.5194/hess-2024-37, 2024
Preprint under review for HESS
Short summary
Short summary
While rainwater is a key resource in crop production, its productivity faces challenges from climate change. Using a simple model of climate, water, and crop yield interactions, we found that rain-scarce croplands in Ethiopia are likely to experience decreases in crop yield during the main growing season, primarily due to future temperature increases. These insights are crucial for shaping future water management plans, policies, and informed decision-making for climate adaptation.
Moritz Laub, Sergey Blagodatsky, Marijn Van de Broek, Samuel Schlichenmaier, Benjapon Kunlanit, Johan Six, Patma Vityakon, and Georg Cadisch
Geosci. Model Dev., 17, 931–956, https://doi.org/10.5194/gmd-17-931-2024, https://doi.org/10.5194/gmd-17-931-2024, 2024
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To manage soil organic matter (SOM) sustainably, we need a better understanding of the role that soil microbes play in aggregate protection. Here, we propose the SAMM model, which connects soil aggregate formation to microbial growth. We tested it against data from a tropical long-term experiment and show that SAMM effectively represents the microbial growth, SOM, and aggregate dynamics and that it can be used to explore the importance of aggregate formation in SOM stabilization.
Claude Raoul Müller, Johan Six, Liesa Brosens, Philipp Baumann, Jean Paolo Gomes Minella, Gerard Govers, and Marijn Van de Broek
EGUsphere, https://doi.org/10.5194/egusphere-2023-2170, https://doi.org/10.5194/egusphere-2023-2170, 2023
Short summary
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Subsoils in the tropics are not yet as extensively studied as in temperate regions. In this study, the conversion of forest to agriculture in a subtropical region affected the concentration of stabilized organic carbon (OC) down to 90 cm depth, while no significant differences between 90 cm and 300 cm were detected. Our results suggest that subsoils below 90 cm are unlikely to accumulate additional stabilized OC through reforestation over decadal periods due to declining OC input with depth.
Moritz Laub, Magdalena Necpalova, Marijn Van de Broek, Marc Corbeels, Samuel Mathu Ndungu, Monicah Wanjiku Mucheru-Muna, Daniel Mugendi, Rebecca Yegon, Wycliffe Waswa, Bernard Vanlauwe, and Johan Six
EGUsphere, https://doi.org/10.5194/egusphere-2023-1738, https://doi.org/10.5194/egusphere-2023-1738, 2023
Short summary
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We used the DayCent model to assess the potential impact of integrated soil fertility management (ISFM) on maize production, soil fertility and greenhouse gas emission in Kenya. After needed adjustments, DayCent could adequately represent the measured mean yields, soil carbon stock changes, and N2O emissions. Our results showed that soil fertility losses could be reduced with ISFM and that, while N2O emissions increased with ISFM, emissions per kg of yield decreased.
Moritz Laub, Marc Corbeels, Antoine Couëdel, Samuel Mathu Ndungu, Monicah Wanjiku Mucheru-Muna, Daniel Mugendi, Magdalena Necpalova, Wycliffe Waswa, Marijn Van de Broek, Bernard Vanlauwe, and Johan Six
SOIL, 9, 301–323, https://doi.org/10.5194/soil-9-301-2023, https://doi.org/10.5194/soil-9-301-2023, 2023
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In sub-Saharan Africa, long-term low-input maize cropping threatens soil fertility. We studied how different quality organic inputs combined with mineral N fertilizer could counteract this. Farmyard manure was the best input to counteract soil carbon loss; mineral N fertilizer had no effect on carbon. Yet, the rates needed to offset soil carbon losses are unrealistic for farmers (>10 t of dry matter per hectare and year). Additional agronomic measures may be needed.
Kristof Van Oost and Johan Six
Biogeosciences, 20, 635–646, https://doi.org/10.5194/bg-20-635-2023, https://doi.org/10.5194/bg-20-635-2023, 2023
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The direction and magnitude of the net erosion-induced land–atmosphere C exchange have been the topic of a big scientific debate for more than a decade now. Many have assumed that erosion leads to a loss of soil carbon to the atmosphere, whereas others have shown that erosion ultimately leads to a carbon sink. Here, we show that the soil carbon erosion source–sink paradox is reconciled when the broad range of temporal and spatial scales at which the underlying processes operate are considered.
Charlotte Decock, Juhwan Lee, Matti Barthel, Elizabeth Verhoeven, Franz Conen, and Johan Six
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-221, https://doi.org/10.5194/bg-2022-221, 2022
Preprint withdrawn
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One of the least well understood processes in the nitrogen (N) cycle is the loss of nitrogen gas (N2), referred to as total denitrification. This is mainly due to the difficulty of quantifying total denitrification in situ. In this study, we developed and tested a novel modeling approach to estimate total denitrification over the depth profile, based on concentrations and isotope values of N2O. Our method will help close N budgets and identify management strategies that reduce N pollution.
Tegawende Léa Jeanne Ilboudo, Lucien NGuessan Diby, Delwendé Innocent Kiba, Tor Gunnar Vågen, Leigh Ann Winowiecki, Hassan Bismarck Nacro, Johan Six, and Emmanuel Frossard
EGUsphere, https://doi.org/10.5194/egusphere-2022-209, https://doi.org/10.5194/egusphere-2022-209, 2022
Preprint withdrawn
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Our results showed that at landscape level SOC stock variability was mainly explained by clay content. We found significant linear positive relationships between VC and SOC stocks for the land uses annual croplands, perennial croplands, grasslands and bushlands without soil depth restrictions until 110 cm. We concluded that in the forest-savanna transition zone, soil properties and topography determine land use, which in turn affects the stocks of SOC and TN and to some extent the VC stocks.
Philipp Baumann, Juhwan Lee, Emmanuel Frossard, Laurie Paule Schönholzer, Lucien Diby, Valérie Kouamé Hgaza, Delwende Innocent Kiba, Andrew Sila, Keith Sheperd, and Johan Six
SOIL, 7, 717–731, https://doi.org/10.5194/soil-7-717-2021, https://doi.org/10.5194/soil-7-717-2021, 2021
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This work delivers openly accessible and validated calibrations for diagnosing 26 soil properties based on mid-infrared spectroscopy. These were developed for four regions in Burkina Faso and Côte d'Ivoire, including 80 fields of smallholder farmers. The models can help to site-specifically and cost-efficiently monitor soil quality and fertility constraints to ameliorate soils and yields of yam or other staple crops in the four regions between the humid forest and the northern Guinean savanna.
Laura Summerauer, Philipp Baumann, Leonardo Ramirez-Lopez, Matti Barthel, Marijn Bauters, Benjamin Bukombe, Mario Reichenbach, Pascal Boeckx, Elizabeth Kearsley, Kristof Van Oost, Bernard Vanlauwe, Dieudonné Chiragaga, Aimé Bisimwa Heri-Kazi, Pieter Moonen, Andrew Sila, Keith Shepherd, Basile Bazirake Mujinya, Eric Van Ranst, Geert Baert, Sebastian Doetterl, and Johan Six
SOIL, 7, 693–715, https://doi.org/10.5194/soil-7-693-2021, https://doi.org/10.5194/soil-7-693-2021, 2021
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We present a soil mid-infrared library with over 1800 samples from central Africa in order to facilitate soil analyses of this highly understudied yet critical area. Together with an existing continental library, we demonstrate a regional analysis and geographical extrapolation to predict total carbon and nitrogen. Our results show accurate predictions and highlight the value that the data contribute to existing libraries. Our library is openly available for public use and for expansion.
Sebastian Doetterl, Rodrigue K. Asifiwe, Geert Baert, Fernando Bamba, Marijn Bauters, Pascal Boeckx, Benjamin Bukombe, Georg Cadisch, Matthew Cooper, Landry N. Cizungu, Alison Hoyt, Clovis Kabaseke, Karsten Kalbitz, Laurent Kidinda, Annina Maier, Moritz Mainka, Julia Mayrock, Daniel Muhindo, Basile B. Mujinya, Serge M. Mukotanyi, Leon Nabahungu, Mario Reichenbach, Boris Rewald, Johan Six, Anna Stegmann, Laura Summerauer, Robin Unseld, Bernard Vanlauwe, Kristof Van Oost, Kris Verheyen, Cordula Vogel, Florian Wilken, and Peter Fiener
Earth Syst. Sci. Data, 13, 4133–4153, https://doi.org/10.5194/essd-13-4133-2021, https://doi.org/10.5194/essd-13-4133-2021, 2021
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The African Tropics are hotspots of modern-day land use change and are of great relevance for the global carbon cycle. Here, we present data collected as part of the DFG-funded project TropSOC along topographic, land use, and geochemical gradients in the eastern Congo Basin and the Albertine Rift. Our database contains spatial and temporal data on soil, vegetation, environmental properties, and land management collected from 136 pristine tropical forest and cropland plots between 2017 and 2020.
Philipp Baumann, Anatol Helfenstein, Andreas Gubler, Armin Keller, Reto Giulio Meuli, Daniel Wächter, Juhwan Lee, Raphael Viscarra Rossel, and Johan Six
SOIL, 7, 525–546, https://doi.org/10.5194/soil-7-525-2021, https://doi.org/10.5194/soil-7-525-2021, 2021
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We developed the Swiss mid-infrared spectral library and a statistical model collection across 4374 soil samples with reference measurements of 16 properties. Our library incorporates soil from 1094 grid locations and 71 long-term monitoring sites. This work confirms once again that nationwide spectral libraries with diverse soils can reliably feed information to a fast chemical diagnosis. Our data-driven reduction of the library has the potential to accurately monitor carbon at the plot scale.
Mario Reichenbach, Peter Fiener, Gina Garland, Marco Griepentrog, Johan Six, and Sebastian Doetterl
SOIL, 7, 453–475, https://doi.org/10.5194/soil-7-453-2021, https://doi.org/10.5194/soil-7-453-2021, 2021
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In deeply weathered tropical rainforest soils of Africa, we found that patterns of soil organic carbon stocks differ between soils developed from geochemically contrasting parent material due to differences in the abundance of organo-mineral complexes, the presence/absence of chemical stabilization mechanisms of carbon with minerals and the presence of fossil organic carbon from sedimentary rocks. Physical stabilization mechanisms by aggregation provide additional protection of soil carbon.
Sophie F. von Fromm, Alison M. Hoyt, Markus Lange, Gifty E. Acquah, Ermias Aynekulu, Asmeret Asefaw Berhe, Stephan M. Haefele, Steve P. McGrath, Keith D. Shepherd, Andrew M. Sila, Johan Six, Erick K. Towett, Susan E. Trumbore, Tor-G. Vågen, Elvis Weullow, Leigh A. Winowiecki, and Sebastian Doetterl
SOIL, 7, 305–332, https://doi.org/10.5194/soil-7-305-2021, https://doi.org/10.5194/soil-7-305-2021, 2021
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We investigated various soil and climate properties that influence soil organic carbon (SOC) concentrations in sub-Saharan Africa. Our findings indicate that climate and geochemistry are equally important for explaining SOC variations. The key SOC-controlling factors are broadly similar to those for temperate regions, despite differences in soil development history between the two regions.
Anatol Helfenstein, Philipp Baumann, Raphael Viscarra Rossel, Andreas Gubler, Stefan Oechslin, and Johan Six
SOIL, 7, 193–215, https://doi.org/10.5194/soil-7-193-2021, https://doi.org/10.5194/soil-7-193-2021, 2021
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In this study, we show that a soil spectral library (SSL) can be used to predict soil carbon at new and very different locations. The importance of this finding is that it requires less time-consuming lab work than calibrating a new model for every local application, while still remaining similar to or more accurate than local models. Furthermore, we show that this method even works for predicting (drained) peat soils, using a SSL with mostly mineral soils containing much less soil carbon.
Simon Baumgartner, Marijn Bauters, Matti Barthel, Travis W. Drake, Landry C. Ntaboba, Basile M. Bazirake, Johan Six, Pascal Boeckx, and Kristof Van Oost
SOIL, 7, 83–94, https://doi.org/10.5194/soil-7-83-2021, https://doi.org/10.5194/soil-7-83-2021, 2021
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We compared stable isotope signatures of soil profiles in different forest ecosystems within the Congo Basin to assess ecosystem-level differences in N cycling, and we examined the local effect of topography on the isotopic signature of soil N. Soil δ15N profiles indicated that the N cycling in in the montane forest is more closed, whereas the lowland forest and Miombo woodland experienced a more open N cycle. Topography only alters soil δ15N values in forests with high erosional forces.
Simon Baumgartner, Matti Barthel, Travis William Drake, Marijn Bauters, Isaac Ahanamungu Makelele, John Kalume Mugula, Laura Summerauer, Nora Gallarotti, Landry Cizungu Ntaboba, Kristof Van Oost, Pascal Boeckx, Sebastian Doetterl, Roland Anton Werner, and Johan Six
Biogeosciences, 17, 6207–6218, https://doi.org/10.5194/bg-17-6207-2020, https://doi.org/10.5194/bg-17-6207-2020, 2020
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Soil respiration is an important carbon flux and key process determining the net ecosystem production of terrestrial ecosystems. The Congo Basin lacks studies quantifying carbon fluxes. We measured soil CO2 fluxes from different forest types in the Congo Basin and were able to show that, even though soil CO2 fluxes are similarly high in lowland and montane forests, the drivers were different: soil moisture in montane forests and C availability in the lowland forests.
Long Ho, Ruben Jerves-Cobo, Matti Barthel, Johan Six, Samuel Bode, Pascal Boeckx, and Peter Goethals
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-311, https://doi.org/10.5194/bg-2020-311, 2020
Revised manuscript not accepted
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Rivers are being polluted by human activities, especially in urban areas. We studied the greenhouse gas (GHG) emissions from an urban river system. The results showed a clear trend between water quality and GHG emissions in which the more polluted the sites were, the higher were their emissions. When river water quality worsened, its contribution to global warming can go up by 10 times. Urban rivers emitted 4-times more than of the amount of GHGs compared to rivers in natural sites.
Marijn Van de Broek, Shiva Ghiasi, Charlotte Decock, Andreas Hund, Samuel Abiven, Cordula Friedli, Roland A. Werner, and Johan Six
Biogeosciences, 17, 2971–2986, https://doi.org/10.5194/bg-17-2971-2020, https://doi.org/10.5194/bg-17-2971-2020, 2020
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Four wheat cultivars were labeled with 13CO2 to quantify the effect of rooting depth and root biomass on the belowground transfer of organic carbon. We found no clear relation between the time since cultivar development and the amount of carbon inputs to the soil. Therefore, the hypothesis that wheat cultivars with a larger root biomass and deeper roots promote carbon stabilization was rejected. The amount of root biomass that will be stabilized in the soil on the long term is, however, unknown.
Stephen J. Harris, Jesper Liisberg, Longlong Xia, Jing Wei, Kerstin Zeyer, Longfei Yu, Matti Barthel, Benjamin Wolf, Bryce F. J. Kelly, Dioni I. Cendón, Thomas Blunier, Johan Six, and Joachim Mohn
Atmos. Meas. Tech., 13, 2797–2831, https://doi.org/10.5194/amt-13-2797-2020, https://doi.org/10.5194/amt-13-2797-2020, 2020
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The latest commercial laser spectrometers have the potential to revolutionize N2O isotope analysis. However, to do so, they must be able to produce trustworthy data. Here, we test the performance of widely used laser spectrometers for ambient air applications and identify instrument-specific dependencies on gas matrix and trace gas concentrations. We then provide a calibration workflow to facilitate the operation of these instruments in order to generate reproducible and accurate data.
Karl Voglmeier, Johan Six, Markus Jocher, and Christof Ammann
Biogeosciences, 16, 1685–1703, https://doi.org/10.5194/bg-16-1685-2019, https://doi.org/10.5194/bg-16-1685-2019, 2019
Tino Colombi, Florian Walder, Lucie Büchi, Marlies Sommer, Kexing Liu, Johan Six, Marcel G. A. van der Heijden, Raphaël Charles, and Thomas Keller
SOIL, 5, 91–105, https://doi.org/10.5194/soil-5-91-2019, https://doi.org/10.5194/soil-5-91-2019, 2019
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The role of soil aeration in carbon sequestration in arable soils has only been explored little, especially at the farm level. The current study, which was conducted on 30 fields that belong to individual farms, reveals a positive relationship between soil gas transport capability and soil organic carbon content. We therefore conclude that soil aeration needs to be accounted for when developing strategies for carbon sequestration in arable soil.
Elizabeth Verhoeven, Matti Barthel, Longfei Yu, Luisella Celi, Daniel Said-Pullicino, Steven Sleutel, Dominika Lewicka-Szczebak, Johan Six, and Charlotte Decock
Biogeosciences, 16, 383–408, https://doi.org/10.5194/bg-16-383-2019, https://doi.org/10.5194/bg-16-383-2019, 2019
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This study utilized state-of-the-art measurements of nitrogen isotopes to evaluate nitrogen cycling and to assess the biological sources of the potent greenhouse gas, N2O, in response to water-saving practices in rice systems. Water-saving practices did emit more N2O, and high N2O production had a lower 15N isotope signature. Modeling and visual interpretation indicate that these emissions mostly came from denitrification or nitrifier denitrification, controlled upstream by nitrification rates.
R. Hüppi, R. Felber, A. Neftel, J. Six, and J. Leifeld
SOIL, 1, 707–717, https://doi.org/10.5194/soil-1-707-2015, https://doi.org/10.5194/soil-1-707-2015, 2015
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Biochar is considered an opportunity to tackle major environmental issues in agriculture. Adding pyrolised organic residues to soil may sequester carbon, increase yields and reduce nitrous oxide emissions from soil. It is unknown, whether the latter is induced by changes in soil pH. We show that biochar application substantially reduces nitrous oxide emissions from a temperate maize cropping system. However, the reduction was only achieved with biochar but not with liming.
C. Decock, J. Lee, M. Necpalova, E. I. P. Pereira, D. M. Tendall, and J. Six
SOIL, 1, 687–694, https://doi.org/10.5194/soil-1-687-2015, https://doi.org/10.5194/soil-1-687-2015, 2015
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Further progress in understanding and mitigating N2O emissions from soil lies within transdisciplinary research that reaches across spatial scales and takes an ambitious look into the future.
M. S. Torn, A. Chabbi, P. Crill, P. J. Hanson, I. A. Janssens, Y. Luo, C. H. Pries, C. Rumpel, M. W. I. Schmidt, J. Six, M. Schrumpf, and B. Zhu
SOIL, 1, 575–582, https://doi.org/10.5194/soil-1-575-2015, https://doi.org/10.5194/soil-1-575-2015, 2015
B. Wolf, L. Merbold, C. Decock, B. Tuzson, E. Harris, J. Six, L. Emmenegger, and J. Mohn
Biogeosciences, 12, 2517–2531, https://doi.org/10.5194/bg-12-2517-2015, https://doi.org/10.5194/bg-12-2517-2015, 2015
S. Doetterl, J.-T. Cornelis, J. Six, S. Bodé, S. Opfergelt, P. Boeckx, and K. Van Oost
Biogeosciences, 12, 1357–1371, https://doi.org/10.5194/bg-12-1357-2015, https://doi.org/10.5194/bg-12-1357-2015, 2015
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We link the mineralogy of soils affected by erosion and deposition to the distribution of soil carbon fractions, their turnover and microbial activity. We show that the weathering status of soils and their history are controlling the stabilization of carbon with minerals. After burial, aggregated C is preserved more efficiently while non-aggregated C can be released and younger C re-sequestered more easily. Weathering changes the effectiveness of stabilization mechanism limiting this C sink.
E. C. Brevik, A. Cerdà, J. Mataix-Solera, L. Pereg, J. N. Quinton, J. Six, and K. Van Oost
SOIL, 1, 117–129, https://doi.org/10.5194/soil-1-117-2015, https://doi.org/10.5194/soil-1-117-2015, 2015
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This paper provides a brief accounting of some of the many ways that the study of soils can be interdisciplinary, therefore giving examples of the types of papers we hope to see submitted to SOIL.
Vira Leng, Rémi Cardinael, Florent Tivet, Vang Seng, Phearum Mark, Pascal Lienhard, Titouan Filloux, Johan Six, Lyda Hok, Stéphane Boulakia, Clever Briedis, João Carlos de Moraes Sá, and Laurent Thuriès
EGUsphere, https://doi.org/10.5194/egusphere-2024-541, https://doi.org/10.5194/egusphere-2024-541, 2024
Short summary
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We assessed the long-term impacts of no-till cropping systems on soil organic carbon and nitrogen dynamics down to 1 m depth under the annual upland crop productions (cassava, maize, and soybean) in the tropical climate of Cambodia. We showed that no-till systems combined with rotations and cover crops could store large amounts of carbon in top and subsoil, in both the mineral organic-matter and particulate organic matter fractions. It also questions nitrogen management in these systems.
Armwell Shumba, Regis Chikowo, Christian Thierfelder, Marc Corbeels, Johan Six, and Rémi Cardinael
SOIL, 10, 151–165, https://doi.org/10.5194/soil-10-151-2024, https://doi.org/10.5194/soil-10-151-2024, 2024
Short summary
Short summary
Conservation agriculture (CA), combining reduced or no tillage, permanent soil cover, and improved rotations, is often promoted as a climate-smart practice. However, our knowledge of the impact of CA on top- and subsoil soil organic carbon (SOC) stocks in the low-input cropping systems of sub-Saharan Africa is rather limited. Using two long-term experimental sites with different soil types, we found that mulch could increase top SOC stocks, but no tillage alone had a slightly negative impact.
Mosisa Tujuba Wakjira, Nadav Peleg, Johan Six, and Peter Molnar
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2024-37, https://doi.org/10.5194/hess-2024-37, 2024
Preprint under review for HESS
Short summary
Short summary
While rainwater is a key resource in crop production, its productivity faces challenges from climate change. Using a simple model of climate, water, and crop yield interactions, we found that rain-scarce croplands in Ethiopia are likely to experience decreases in crop yield during the main growing season, primarily due to future temperature increases. These insights are crucial for shaping future water management plans, policies, and informed decision-making for climate adaptation.
Moritz Laub, Sergey Blagodatsky, Marijn Van de Broek, Samuel Schlichenmaier, Benjapon Kunlanit, Johan Six, Patma Vityakon, and Georg Cadisch
Geosci. Model Dev., 17, 931–956, https://doi.org/10.5194/gmd-17-931-2024, https://doi.org/10.5194/gmd-17-931-2024, 2024
Short summary
Short summary
To manage soil organic matter (SOM) sustainably, we need a better understanding of the role that soil microbes play in aggregate protection. Here, we propose the SAMM model, which connects soil aggregate formation to microbial growth. We tested it against data from a tropical long-term experiment and show that SAMM effectively represents the microbial growth, SOM, and aggregate dynamics and that it can be used to explore the importance of aggregate formation in SOM stabilization.
Gina Garland, John Koestel, Alice Johannes, Olivier Heller, Sebastian Doetterl, Dani Or, and Thomas Keller
SOIL, 10, 23–31, https://doi.org/10.5194/soil-10-23-2024, https://doi.org/10.5194/soil-10-23-2024, 2024
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The concept of soil aggregates is hotly debated, leading to confusion about their function or relevancy to soil processes. We propose that the use of conceptual figures showing detached and isolated aggregates can be misleading and has contributed to this skepticism. Here, we conceptually illustrate how aggregates can form and dissipate within the context of undisturbed soils, highlighting the fact that aggregates do not necessarily need to have distinct physical boundaries.
Claude Raoul Müller, Johan Six, Liesa Brosens, Philipp Baumann, Jean Paolo Gomes Minella, Gerard Govers, and Marijn Van de Broek
EGUsphere, https://doi.org/10.5194/egusphere-2023-2170, https://doi.org/10.5194/egusphere-2023-2170, 2023
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Subsoils in the tropics are not yet as extensively studied as in temperate regions. In this study, the conversion of forest to agriculture in a subtropical region affected the concentration of stabilized organic carbon (OC) down to 90 cm depth, while no significant differences between 90 cm and 300 cm were detected. Our results suggest that subsoils below 90 cm are unlikely to accumulate additional stabilized OC through reforestation over decadal periods due to declining OC input with depth.
Moritz Laub, Magdalena Necpalova, Marijn Van de Broek, Marc Corbeels, Samuel Mathu Ndungu, Monicah Wanjiku Mucheru-Muna, Daniel Mugendi, Rebecca Yegon, Wycliffe Waswa, Bernard Vanlauwe, and Johan Six
EGUsphere, https://doi.org/10.5194/egusphere-2023-1738, https://doi.org/10.5194/egusphere-2023-1738, 2023
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We used the DayCent model to assess the potential impact of integrated soil fertility management (ISFM) on maize production, soil fertility and greenhouse gas emission in Kenya. After needed adjustments, DayCent could adequately represent the measured mean yields, soil carbon stock changes, and N2O emissions. Our results showed that soil fertility losses could be reduced with ISFM and that, while N2O emissions increased with ISFM, emissions per kg of yield decreased.
Shane W. Stoner, Marion Schrumpf, Alison Hoyt, Carlos A. Sierra, Sebastian Doetterl, Valier Galy, and Susan Trumbore
Biogeosciences, 20, 3151–3163, https://doi.org/10.5194/bg-20-3151-2023, https://doi.org/10.5194/bg-20-3151-2023, 2023
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Soils store more carbon (C) than any other terrestrial C reservoir, but the processes that control how much C stays in soil, and for how long, are very complex. Here, we used a recent method that involves heating soil in the lab to measure the range of C ages in soil. We found that most C in soil is decades to centuries old, while some stays for much shorter times (days to months), and some is thousands of years old. Such detail helps us to estimate how soil C may react to changing climate.
Moritz Laub, Marc Corbeels, Antoine Couëdel, Samuel Mathu Ndungu, Monicah Wanjiku Mucheru-Muna, Daniel Mugendi, Magdalena Necpalova, Wycliffe Waswa, Marijn Van de Broek, Bernard Vanlauwe, and Johan Six
SOIL, 9, 301–323, https://doi.org/10.5194/soil-9-301-2023, https://doi.org/10.5194/soil-9-301-2023, 2023
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In sub-Saharan Africa, long-term low-input maize cropping threatens soil fertility. We studied how different quality organic inputs combined with mineral N fertilizer could counteract this. Farmyard manure was the best input to counteract soil carbon loss; mineral N fertilizer had no effect on carbon. Yet, the rates needed to offset soil carbon losses are unrealistic for farmers (>10 t of dry matter per hectare and year). Additional agronomic measures may be needed.
Kristof Van Oost and Johan Six
Biogeosciences, 20, 635–646, https://doi.org/10.5194/bg-20-635-2023, https://doi.org/10.5194/bg-20-635-2023, 2023
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The direction and magnitude of the net erosion-induced land–atmosphere C exchange have been the topic of a big scientific debate for more than a decade now. Many have assumed that erosion leads to a loss of soil carbon to the atmosphere, whereas others have shown that erosion ultimately leads to a carbon sink. Here, we show that the soil carbon erosion source–sink paradox is reconciled when the broad range of temporal and spatial scales at which the underlying processes operate are considered.
Charlotte Decock, Juhwan Lee, Matti Barthel, Elizabeth Verhoeven, Franz Conen, and Johan Six
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-221, https://doi.org/10.5194/bg-2022-221, 2022
Preprint withdrawn
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One of the least well understood processes in the nitrogen (N) cycle is the loss of nitrogen gas (N2), referred to as total denitrification. This is mainly due to the difficulty of quantifying total denitrification in situ. In this study, we developed and tested a novel modeling approach to estimate total denitrification over the depth profile, based on concentrations and isotope values of N2O. Our method will help close N budgets and identify management strategies that reduce N pollution.
Tegawende Léa Jeanne Ilboudo, Lucien NGuessan Diby, Delwendé Innocent Kiba, Tor Gunnar Vågen, Leigh Ann Winowiecki, Hassan Bismarck Nacro, Johan Six, and Emmanuel Frossard
EGUsphere, https://doi.org/10.5194/egusphere-2022-209, https://doi.org/10.5194/egusphere-2022-209, 2022
Preprint withdrawn
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Our results showed that at landscape level SOC stock variability was mainly explained by clay content. We found significant linear positive relationships between VC and SOC stocks for the land uses annual croplands, perennial croplands, grasslands and bushlands without soil depth restrictions until 110 cm. We concluded that in the forest-savanna transition zone, soil properties and topography determine land use, which in turn affects the stocks of SOC and TN and to some extent the VC stocks.
Moritz Mainka, Laura Summerauer, Daniel Wasner, Gina Garland, Marco Griepentrog, Asmeret Asefaw Berhe, and Sebastian Doetterl
Biogeosciences, 19, 1675–1689, https://doi.org/10.5194/bg-19-1675-2022, https://doi.org/10.5194/bg-19-1675-2022, 2022
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The largest share of terrestrial carbon is stored in soils, making them highly relevant as regards global change. Yet, the mechanisms governing soil carbon stabilization are not well understood. The present study contributes to a better understanding of these processes. We show that qualitative changes in soil organic matter (SOM) co-vary with alterations of the soil matrix following soil weathering. Hence, the type of SOM that is stabilized in soils might change as soils develop.
Rey Harvey Suello, Simon Lucas Hernandez, Steven Bouillon, Jean-Philippe Belliard, Luis Dominguez-Granda, Marijn Van de Broek, Andrea Mishell Rosado Moncayo, John Ramos Veliz, Karem Pollette Ramirez, Gerard Govers, and Stijn Temmerman
Biogeosciences, 19, 1571–1585, https://doi.org/10.5194/bg-19-1571-2022, https://doi.org/10.5194/bg-19-1571-2022, 2022
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This research shows indications that the age of the mangrove forest and its position along a deltaic gradient (upstream–downstream) play a vital role in the amount and sources of carbon stored in the mangrove sediments. Our findings also imply that carbon capture by the mangrove ecosystem itself contributes partly but relatively little to long-term sediment organic carbon storage. This finding is particularly relevant for budgeting the potential of mangrove ecosystems to mitigate climate change.
Florian Lauryssen, Philippe Crombé, Tom Maris, Elliot Van Maldegem, Marijn Van de Broek, Stijn Temmerman, and Erik Smolders
Biogeosciences, 19, 763–776, https://doi.org/10.5194/bg-19-763-2022, https://doi.org/10.5194/bg-19-763-2022, 2022
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Surface waters in lowland regions have a poor surface water quality, mainly due to excess nutrients like phosphate. Therefore, we wanted to know the phosphate levels without humans, also called the pre-industrial background. Phosphate binds strongly to sediment particles, suspended in the river water. In this research we used sediments deposited by a river as an archive for surface water phosphate back to 1800 CE. Pre-industrial phosphate levels were estimated at one-third of the modern levels.
Pengzhi Zhao, Daniel Joseph Fallu, Sara Cucchiaro, Paolo Tarolli, Clive Waddington, David Cockcroft, Lisa Snape, Andreas Lang, Sebastian Doetterl, Antony G. Brown, and Kristof Van Oost
Biogeosciences, 18, 6301–6312, https://doi.org/10.5194/bg-18-6301-2021, https://doi.org/10.5194/bg-18-6301-2021, 2021
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We investigate the factors controlling the soil organic carbon (SOC) stability and temperature sensitivity of abandoned prehistoric agricultural terrace soils. Results suggest that the burial of former topsoil due to terracing provided an SOC stabilization mechanism. Both the soil C : N ratio and SOC mineral protection regulate soil SOC temperature sensitivity. However, which mechanism predominantly controls SOC temperature sensitivity depends on the age of the buried terrace soils.
Philipp Baumann, Juhwan Lee, Emmanuel Frossard, Laurie Paule Schönholzer, Lucien Diby, Valérie Kouamé Hgaza, Delwende Innocent Kiba, Andrew Sila, Keith Sheperd, and Johan Six
SOIL, 7, 717–731, https://doi.org/10.5194/soil-7-717-2021, https://doi.org/10.5194/soil-7-717-2021, 2021
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This work delivers openly accessible and validated calibrations for diagnosing 26 soil properties based on mid-infrared spectroscopy. These were developed for four regions in Burkina Faso and Côte d'Ivoire, including 80 fields of smallholder farmers. The models can help to site-specifically and cost-efficiently monitor soil quality and fertility constraints to ameliorate soils and yields of yam or other staple crops in the four regions between the humid forest and the northern Guinean savanna.
Laura Summerauer, Philipp Baumann, Leonardo Ramirez-Lopez, Matti Barthel, Marijn Bauters, Benjamin Bukombe, Mario Reichenbach, Pascal Boeckx, Elizabeth Kearsley, Kristof Van Oost, Bernard Vanlauwe, Dieudonné Chiragaga, Aimé Bisimwa Heri-Kazi, Pieter Moonen, Andrew Sila, Keith Shepherd, Basile Bazirake Mujinya, Eric Van Ranst, Geert Baert, Sebastian Doetterl, and Johan Six
SOIL, 7, 693–715, https://doi.org/10.5194/soil-7-693-2021, https://doi.org/10.5194/soil-7-693-2021, 2021
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We present a soil mid-infrared library with over 1800 samples from central Africa in order to facilitate soil analyses of this highly understudied yet critical area. Together with an existing continental library, we demonstrate a regional analysis and geographical extrapolation to predict total carbon and nitrogen. Our results show accurate predictions and highlight the value that the data contribute to existing libraries. Our library is openly available for public use and for expansion.
Benjamin Bukombe, Peter Fiener, Alison M. Hoyt, Laurent K. Kidinda, and Sebastian Doetterl
SOIL, 7, 639–659, https://doi.org/10.5194/soil-7-639-2021, https://doi.org/10.5194/soil-7-639-2021, 2021
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Through a laboratory incubation experiment, we investigated the spatial patterns of specific maximum heterotrophic respiration in tropical African mountain forest soils developed from contrasting parent material along slope gradients. We found distinct differences in soil respiration between soil depths and geochemical regions related to soil fertility and the chemistry of the soil solution. The topographic origin of our samples was not a major determinant of the observed rates of respiration.
Sebastian Doetterl, Rodrigue K. Asifiwe, Geert Baert, Fernando Bamba, Marijn Bauters, Pascal Boeckx, Benjamin Bukombe, Georg Cadisch, Matthew Cooper, Landry N. Cizungu, Alison Hoyt, Clovis Kabaseke, Karsten Kalbitz, Laurent Kidinda, Annina Maier, Moritz Mainka, Julia Mayrock, Daniel Muhindo, Basile B. Mujinya, Serge M. Mukotanyi, Leon Nabahungu, Mario Reichenbach, Boris Rewald, Johan Six, Anna Stegmann, Laura Summerauer, Robin Unseld, Bernard Vanlauwe, Kristof Van Oost, Kris Verheyen, Cordula Vogel, Florian Wilken, and Peter Fiener
Earth Syst. Sci. Data, 13, 4133–4153, https://doi.org/10.5194/essd-13-4133-2021, https://doi.org/10.5194/essd-13-4133-2021, 2021
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The African Tropics are hotspots of modern-day land use change and are of great relevance for the global carbon cycle. Here, we present data collected as part of the DFG-funded project TropSOC along topographic, land use, and geochemical gradients in the eastern Congo Basin and the Albertine Rift. Our database contains spatial and temporal data on soil, vegetation, environmental properties, and land management collected from 136 pristine tropical forest and cropland plots between 2017 and 2020.
Philipp Baumann, Anatol Helfenstein, Andreas Gubler, Armin Keller, Reto Giulio Meuli, Daniel Wächter, Juhwan Lee, Raphael Viscarra Rossel, and Johan Six
SOIL, 7, 525–546, https://doi.org/10.5194/soil-7-525-2021, https://doi.org/10.5194/soil-7-525-2021, 2021
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We developed the Swiss mid-infrared spectral library and a statistical model collection across 4374 soil samples with reference measurements of 16 properties. Our library incorporates soil from 1094 grid locations and 71 long-term monitoring sites. This work confirms once again that nationwide spectral libraries with diverse soils can reliably feed information to a fast chemical diagnosis. Our data-driven reduction of the library has the potential to accurately monitor carbon at the plot scale.
Mario Reichenbach, Peter Fiener, Gina Garland, Marco Griepentrog, Johan Six, and Sebastian Doetterl
SOIL, 7, 453–475, https://doi.org/10.5194/soil-7-453-2021, https://doi.org/10.5194/soil-7-453-2021, 2021
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In deeply weathered tropical rainforest soils of Africa, we found that patterns of soil organic carbon stocks differ between soils developed from geochemically contrasting parent material due to differences in the abundance of organo-mineral complexes, the presence/absence of chemical stabilization mechanisms of carbon with minerals and the presence of fossil organic carbon from sedimentary rocks. Physical stabilization mechanisms by aggregation provide additional protection of soil carbon.
Joseph Tamale, Roman Hüppi, Marco Griepentrog, Laban Frank Turyagyenda, Matti Barthel, Sebastian Doetterl, Peter Fiener, and Oliver van Straaten
SOIL, 7, 433–451, https://doi.org/10.5194/soil-7-433-2021, https://doi.org/10.5194/soil-7-433-2021, 2021
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Soil greenhouse gas (GHG) fluxes were measured monthly from nitrogen (N), phosphorous (P), N and P, and control plots of the first nutrient manipulation experiment located in an African pristine tropical forest using static chambers. The results suggest (1) contrasting soil GHG responses to nutrient addition, hence highlighting the complexity of the tropical forests, and (2) that the feedback of tropical forests to the global soil GHG budget could be altered by changes in N and P availability.
Florian Wilken, Peter Fiener, Michael Ketterer, Katrin Meusburger, Daniel Iragi Muhindo, Kristof van Oost, and Sebastian Doetterl
SOIL, 7, 399–414, https://doi.org/10.5194/soil-7-399-2021, https://doi.org/10.5194/soil-7-399-2021, 2021
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This study demonstrates the usability of fallout radionuclides 239Pu and 240Pu as a tool to assess soil degradation processes in tropical Africa, which is particularly valuable in regions with limited infrastructure and challenging monitoring conditions for landscape-scale soil degradation monitoring. The study shows no indication of soil redistribution in forest sites but substantial soil redistribution in cropland (sedimentation >40 cm in 55 years) with high variability.
Sophie F. von Fromm, Alison M. Hoyt, Markus Lange, Gifty E. Acquah, Ermias Aynekulu, Asmeret Asefaw Berhe, Stephan M. Haefele, Steve P. McGrath, Keith D. Shepherd, Andrew M. Sila, Johan Six, Erick K. Towett, Susan E. Trumbore, Tor-G. Vågen, Elvis Weullow, Leigh A. Winowiecki, and Sebastian Doetterl
SOIL, 7, 305–332, https://doi.org/10.5194/soil-7-305-2021, https://doi.org/10.5194/soil-7-305-2021, 2021
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We investigated various soil and climate properties that influence soil organic carbon (SOC) concentrations in sub-Saharan Africa. Our findings indicate that climate and geochemistry are equally important for explaining SOC variations. The key SOC-controlling factors are broadly similar to those for temperate regions, despite differences in soil development history between the two regions.
Anatol Helfenstein, Philipp Baumann, Raphael Viscarra Rossel, Andreas Gubler, Stefan Oechslin, and Johan Six
SOIL, 7, 193–215, https://doi.org/10.5194/soil-7-193-2021, https://doi.org/10.5194/soil-7-193-2021, 2021
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In this study, we show that a soil spectral library (SSL) can be used to predict soil carbon at new and very different locations. The importance of this finding is that it requires less time-consuming lab work than calibrating a new model for every local application, while still remaining similar to or more accurate than local models. Furthermore, we show that this method even works for predicting (drained) peat soils, using a SSL with mostly mineral soils containing much less soil carbon.
Simon Baumgartner, Marijn Bauters, Matti Barthel, Travis W. Drake, Landry C. Ntaboba, Basile M. Bazirake, Johan Six, Pascal Boeckx, and Kristof Van Oost
SOIL, 7, 83–94, https://doi.org/10.5194/soil-7-83-2021, https://doi.org/10.5194/soil-7-83-2021, 2021
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We compared stable isotope signatures of soil profiles in different forest ecosystems within the Congo Basin to assess ecosystem-level differences in N cycling, and we examined the local effect of topography on the isotopic signature of soil N. Soil δ15N profiles indicated that the N cycling in in the montane forest is more closed, whereas the lowland forest and Miombo woodland experienced a more open N cycle. Topography only alters soil δ15N values in forests with high erosional forces.
Simon Baumgartner, Matti Barthel, Travis William Drake, Marijn Bauters, Isaac Ahanamungu Makelele, John Kalume Mugula, Laura Summerauer, Nora Gallarotti, Landry Cizungu Ntaboba, Kristof Van Oost, Pascal Boeckx, Sebastian Doetterl, Roland Anton Werner, and Johan Six
Biogeosciences, 17, 6207–6218, https://doi.org/10.5194/bg-17-6207-2020, https://doi.org/10.5194/bg-17-6207-2020, 2020
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Soil respiration is an important carbon flux and key process determining the net ecosystem production of terrestrial ecosystems. The Congo Basin lacks studies quantifying carbon fluxes. We measured soil CO2 fluxes from different forest types in the Congo Basin and were able to show that, even though soil CO2 fluxes are similarly high in lowland and montane forests, the drivers were different: soil moisture in montane forests and C availability in the lowland forests.
Laurent K. Kidinda, Folasade K. Olagoke, Cordula Vogel, Karsten Kalbitz, and Sebastian Doetterl
SOIL Discuss., https://doi.org/10.5194/soil-2020-80, https://doi.org/10.5194/soil-2020-80, 2020
Preprint withdrawn
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In deeply weathered tropical rainforest soils of Africa, we found that patterns of microbial processes differ between soils developed from geochemically contrasting parent materials due to differences in resource availability. Across investigated geochemical regions and soil depths, soil microbes were P-limited rather than N-limited. Topsoil microbes were more C-limited than their subsoil counterparts but inversely P-limited.
Long Ho, Ruben Jerves-Cobo, Matti Barthel, Johan Six, Samuel Bode, Pascal Boeckx, and Peter Goethals
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-311, https://doi.org/10.5194/bg-2020-311, 2020
Revised manuscript not accepted
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Rivers are being polluted by human activities, especially in urban areas. We studied the greenhouse gas (GHG) emissions from an urban river system. The results showed a clear trend between water quality and GHG emissions in which the more polluted the sites were, the higher were their emissions. When river water quality worsened, its contribution to global warming can go up by 10 times. Urban rivers emitted 4-times more than of the amount of GHGs compared to rivers in natural sites.
Marijn Van de Broek, Shiva Ghiasi, Charlotte Decock, Andreas Hund, Samuel Abiven, Cordula Friedli, Roland A. Werner, and Johan Six
Biogeosciences, 17, 2971–2986, https://doi.org/10.5194/bg-17-2971-2020, https://doi.org/10.5194/bg-17-2971-2020, 2020
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Four wheat cultivars were labeled with 13CO2 to quantify the effect of rooting depth and root biomass on the belowground transfer of organic carbon. We found no clear relation between the time since cultivar development and the amount of carbon inputs to the soil. Therefore, the hypothesis that wheat cultivars with a larger root biomass and deeper roots promote carbon stabilization was rejected. The amount of root biomass that will be stabilized in the soil on the long term is, however, unknown.
Stephen J. Harris, Jesper Liisberg, Longlong Xia, Jing Wei, Kerstin Zeyer, Longfei Yu, Matti Barthel, Benjamin Wolf, Bryce F. J. Kelly, Dioni I. Cendón, Thomas Blunier, Johan Six, and Joachim Mohn
Atmos. Meas. Tech., 13, 2797–2831, https://doi.org/10.5194/amt-13-2797-2020, https://doi.org/10.5194/amt-13-2797-2020, 2020
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The latest commercial laser spectrometers have the potential to revolutionize N2O isotope analysis. However, to do so, they must be able to produce trustworthy data. Here, we test the performance of widely used laser spectrometers for ambient air applications and identify instrument-specific dependencies on gas matrix and trace gas concentrations. We then provide a calibration workflow to facilitate the operation of these instruments in order to generate reproducible and accurate data.
Marco Pfeiffer, José Padarian, Rodrigo Osorio, Nelson Bustamante, Guillermo Federico Olmedo, Mario Guevara, Felipe Aburto, Francisco Albornoz, Monica Antilén, Elías Araya, Eduardo Arellano, Maialen Barret, Juan Barrera, Pascal Boeckx, Margarita Briceño, Sally Bunning, Lea Cabrol, Manuel Casanova, Pablo Cornejo, Fabio Corradini, Gustavo Curaqueo, Sebastian Doetterl, Paola Duran, Mauricio Escudey, Angelina Espinoza, Samuel Francke, Juan Pablo Fuentes, Marcel Fuentes, Gonzalo Gajardo, Rafael García, Audrey Gallaud, Mauricio Galleguillos, Andrés Gomez, Marcela Hidalgo, Jorge Ivelic-Sáez, Lwando Mashalaba, Francisco Matus, Francisco Meza, Maria de la Luz Mora, Jorge Mora, Cristina Muñoz, Pablo Norambuena, Carolina Olivera, Carlos Ovalle, Marcelo Panichini, Aníbal Pauchard, Jorge F. Pérez-Quezada, Sergio Radic, José Ramirez, Nicolás Riveras, Germán Ruiz, Osvaldo Salazar, Iván Salgado, Oscar Seguel, Maria Sepúlveda, Carlos Sierra, Yasna Tapia, Francisco Tapia, Balfredo Toledo, José Miguel Torrico, Susana Valle, Ronald Vargas, Michael Wolff, and Erick Zagal
Earth Syst. Sci. Data, 12, 457–468, https://doi.org/10.5194/essd-12-457-2020, https://doi.org/10.5194/essd-12-457-2020, 2020
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The CHLSOC database is the biggest soil organic carbon (SOC) database that has been compiled for Chile yet, comprising 13 612 data points. This database is the product of the compilation of numerous sources including unpublished and difficult-to-access data, allowing us to fill numerous spatial gaps where no SOC estimates were publicly available before. The values of SOC compiled in CHLSOC have a wide range, reflecting the variety of ecosystems that exists in Chile.
Corey R. Lawrence, Jeffrey Beem-Miller, Alison M. Hoyt, Grey Monroe, Carlos A. Sierra, Shane Stoner, Katherine Heckman, Joseph C. Blankinship, Susan E. Crow, Gavin McNicol, Susan Trumbore, Paul A. Levine, Olga Vindušková, Katherine Todd-Brown, Craig Rasmussen, Caitlin E. Hicks Pries, Christina Schädel, Karis McFarlane, Sebastian Doetterl, Christine Hatté, Yujie He, Claire Treat, Jennifer W. Harden, Margaret S. Torn, Cristian Estop-Aragonés, Asmeret Asefaw Berhe, Marco Keiluweit, Ágatha Della Rosa Kuhnen, Erika Marin-Spiotta, Alain F. Plante, Aaron Thompson, Zheng Shi, Joshua P. Schimel, Lydia J. S. Vaughn, Sophie F. von Fromm, and Rota Wagai
Earth Syst. Sci. Data, 12, 61–76, https://doi.org/10.5194/essd-12-61-2020, https://doi.org/10.5194/essd-12-61-2020, 2020
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The International Soil Radiocarbon Database (ISRaD) is an an open-source archive of soil data focused on datasets including radiocarbon measurements. ISRaD includes data from bulk or
whole soils, distinct soil carbon pools isolated in the laboratory by a variety of soil fractionation methods, samples of soil gas or water collected interstitially from within an intact soil profile, CO2 gas isolated from laboratory soil incubations, and fluxes collected in situ from a soil surface.
Karl Voglmeier, Johan Six, Markus Jocher, and Christof Ammann
Biogeosciences, 16, 1685–1703, https://doi.org/10.5194/bg-16-1685-2019, https://doi.org/10.5194/bg-16-1685-2019, 2019
Tino Colombi, Florian Walder, Lucie Büchi, Marlies Sommer, Kexing Liu, Johan Six, Marcel G. A. van der Heijden, Raphaël Charles, and Thomas Keller
SOIL, 5, 91–105, https://doi.org/10.5194/soil-5-91-2019, https://doi.org/10.5194/soil-5-91-2019, 2019
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The role of soil aeration in carbon sequestration in arable soils has only been explored little, especially at the farm level. The current study, which was conducted on 30 fields that belong to individual farms, reveals a positive relationship between soil gas transport capability and soil organic carbon content. We therefore conclude that soil aeration needs to be accounted for when developing strategies for carbon sequestration in arable soil.
Elizabeth Verhoeven, Matti Barthel, Longfei Yu, Luisella Celi, Daniel Said-Pullicino, Steven Sleutel, Dominika Lewicka-Szczebak, Johan Six, and Charlotte Decock
Biogeosciences, 16, 383–408, https://doi.org/10.5194/bg-16-383-2019, https://doi.org/10.5194/bg-16-383-2019, 2019
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This study utilized state-of-the-art measurements of nitrogen isotopes to evaluate nitrogen cycling and to assess the biological sources of the potent greenhouse gas, N2O, in response to water-saving practices in rice systems. Water-saving practices did emit more N2O, and high N2O production had a lower 15N isotope signature. Modeling and visual interpretation indicate that these emissions mostly came from denitrification or nitrifier denitrification, controlled upstream by nitrification rates.
Marijn Van de Broek, Stijn Temmerman, Roel Merckx, and Gerard Govers
Biogeosciences, 13, 6611–6624, https://doi.org/10.5194/bg-13-6611-2016, https://doi.org/10.5194/bg-13-6611-2016, 2016
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The results of this study on the organic carbon (OC) stocks of tidal marshes show that variations in OC stocks along estuaries are important and should be taken into account to make accurate estimates of the total amount of OC stored in these ecosystems. Moreover, our results clearly show that most studies underestimate the variation in OC stocks along estuaries due to a shallow sampling depth, neglecting the variation in OC decomposition after burial along estuaries.
R. Hüppi, R. Felber, A. Neftel, J. Six, and J. Leifeld
SOIL, 1, 707–717, https://doi.org/10.5194/soil-1-707-2015, https://doi.org/10.5194/soil-1-707-2015, 2015
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Biochar is considered an opportunity to tackle major environmental issues in agriculture. Adding pyrolised organic residues to soil may sequester carbon, increase yields and reduce nitrous oxide emissions from soil. It is unknown, whether the latter is induced by changes in soil pH. We show that biochar application substantially reduces nitrous oxide emissions from a temperate maize cropping system. However, the reduction was only achieved with biochar but not with liming.
C. Decock, J. Lee, M. Necpalova, E. I. P. Pereira, D. M. Tendall, and J. Six
SOIL, 1, 687–694, https://doi.org/10.5194/soil-1-687-2015, https://doi.org/10.5194/soil-1-687-2015, 2015
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Further progress in understanding and mitigating N2O emissions from soil lies within transdisciplinary research that reaches across spatial scales and takes an ambitious look into the future.
M. S. Torn, A. Chabbi, P. Crill, P. J. Hanson, I. A. Janssens, Y. Luo, C. H. Pries, C. Rumpel, M. W. I. Schmidt, J. Six, M. Schrumpf, and B. Zhu
SOIL, 1, 575–582, https://doi.org/10.5194/soil-1-575-2015, https://doi.org/10.5194/soil-1-575-2015, 2015
B. Wolf, L. Merbold, C. Decock, B. Tuzson, E. Harris, J. Six, L. Emmenegger, and J. Mohn
Biogeosciences, 12, 2517–2531, https://doi.org/10.5194/bg-12-2517-2015, https://doi.org/10.5194/bg-12-2517-2015, 2015
S. Doetterl, J.-T. Cornelis, J. Six, S. Bodé, S. Opfergelt, P. Boeckx, and K. Van Oost
Biogeosciences, 12, 1357–1371, https://doi.org/10.5194/bg-12-1357-2015, https://doi.org/10.5194/bg-12-1357-2015, 2015
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We link the mineralogy of soils affected by erosion and deposition to the distribution of soil carbon fractions, their turnover and microbial activity. We show that the weathering status of soils and their history are controlling the stabilization of carbon with minerals. After burial, aggregated C is preserved more efficiently while non-aggregated C can be released and younger C re-sequestered more easily. Weathering changes the effectiveness of stabilization mechanism limiting this C sink.
E. C. Brevik, A. Cerdà, J. Mataix-Solera, L. Pereg, J. N. Quinton, J. Six, and K. Van Oost
SOIL, 1, 117–129, https://doi.org/10.5194/soil-1-117-2015, https://doi.org/10.5194/soil-1-117-2015, 2015
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This paper provides a brief accounting of some of the many ways that the study of soils can be interdisciplinary, therefore giving examples of the types of papers we hope to see submitted to SOIL.
Related subject area
Soils and biogeochemical cycling
Cover crops improve soil structure and change organic carbon distribution in macroaggregate fractions
Soil carbon, nitrogen, and phosphorus storage in juniper–oak savanna: role of vegetation and geology
Organic matters, but inorganic matters too: column examination of elevated mercury sorption on low organic matter aquifer material using concentrations and stable isotope ratios
Contrasting potential for biological N2 fixation at three polluted central European Sphagnum peat bogs: combining the 15N2-tracer and natural-abundance isotope approaches
Soil organic carbon stocks did not change after 130 years of afforestation on a former Swiss Alpine pasture
Shifts in controls and abundance of particulate and mineral-associated organic matter fractions among subfield yield stability zones
Land inclination controls CO2 and N2O fluxes, but not CH4 uptake, in a temperate upland forest soil
Tropical Andosol organic carbon quality and degradability in relation to soil geochemistry as affected by land use
Elemental stoichiometry and Rock-Eval® thermal stability of organic matter in French topsoils
Oil-palm management alters the spatial distribution of amorphous silica and mobile silicon in topsoils
Semantics about soil organic carbon storage: DATA4C+, a comprehensive thesaurus and classification of management practices in agriculture and forestry
Forest liming in the face of climate change: the implications of restorative liming for soil organic carbon in mature German forests
Biotic factors dominantly determine soil inorganic carbon stock across Tibetan alpine grasslands
Effects of returning corn straw and fermented corn straw to fields on the soil organic carbon pools and humus composition
Soil nutrient contents and stoichiometry within aggregate size classes varied with tea plantation age and soil depth in southern Guangxi in China
Land use impact on carbon mineralization in well aerated soils is mainly explained by variations of particulate organic matter rather than of soil structure
Inclusion of biochar in a C dynamics model based on observations from an 8-year field experiment
Synergy between compost and cover crops in a Mediterranean row crop system leads to increased subsoil carbon storage
Phosphorus dynamics during early soil development in a cold desert: insights from oxygen isotopes in phosphate
Transformation of n-alkanes from plant to soil: a review
Heterotrophic soil respiration and carbon cycling in geochemically distinct African tropical forest soils
Soil organic carbon mobility in equatorial podzols: soil column experiments
Microbial activity responses to water stress in agricultural soils from simple and complex crop rotations
The role of geochemistry in organic carbon stabilization against microbial decomposition in tropical rainforest soils
Geogenic organic carbon in terrestrial sediments and its contribution to total soil carbon
Aluminous clay and pedogenic Fe oxides modulate aggregation and related carbon contents in soils of the humid tropics
Continental-scale controls on soil organic carbon across sub-Saharan Africa
Modelling of long-term Zn, Cu, Cd and Pb dynamics from soils fertilised with organic amendments
Stable isotope signatures of soil nitrogen on an environmental–geomorphic gradient within the Congo Basin
Iron and aluminum association with microbially processed organic matter via meso-density aggregate formation across soils: organo-metallic glue hypothesis
Land-use perturbations in ley grassland decouple the degradation of ancient soil organic matter from the storage of newly derived carbon inputs
Switch of fungal to bacterial degradation in natural, drained and rewetted oligotrophic peatlands reflected in δ15N and fatty acid composition
Catchment export of base cations: improved mineral dissolution kinetics influence the role of water transit time
Boreal-forest soil chemistry drives soil organic carbon bioreactivity along a 314-year fire chronosequence
Ramped thermal analysis for isolating biologically meaningful soil organic matter fractions with distinct residence times
Variations in soil chemical and physical properties explain basin-wide Amazon forest soil carbon concentrations
Lithology- and climate-controlled soil aggregate-size distribution and organic carbon stability in the Peruvian Andes
Evaluating the effects of soil erosion and productivity decline on soil carbon dynamics using a model-based approach
Base cations in the soil bank: non-exchangeable pools may sustain centuries of net loss to forestry and leaching
Short-range-order minerals as powerful factors explaining deep soil organic carbon stock distribution: the case of a coffee agroforestry plantation on Andosols in Costa Rica
A new look at an old concept: using 15N2O isotopomers to understand the relationship between soil moisture and N2O production pathways
Assessing the impact of acid rain and forest harvest intensity with the HD-MINTEQ model – soil chemistry of three Swedish conifer sites from 1880 to 2080
Dynamic modelling of weathering rates – the benefit over steady-state modelling
Aluminium and base cation chemistry in dynamic acidification models – need for a reappraisal?
Challenges of soil carbon sequestration in the NENA region
Continental soil drivers of ammonium and nitrate in Australia
Comment on “Soil organic stocks are systematically overestimated by misuse of the parameters bulk density and rock fragment content” by Poeplau et al. (2017)
Hot regions of labile and stable soil organic carbon in Germany – Spatial variability and driving factors
Potential short-term losses of N2O and N2 from high concentrations of biogas digestate in arable soils
A deeper look at the relationship between root carbon pools and the vertical distribution of the soil carbon pool
Norman Gentsch, Florin Laura Riechers, Jens Boy, Dörte Schweneker, Ulf Feuerstein, Diana Heuermann, and Georg Guggenberger
SOIL, 10, 139–150, https://doi.org/10.5194/soil-10-139-2024, https://doi.org/10.5194/soil-10-139-2024, 2024
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Cover crops have substantial impacts on soil properties, but so far it is not clear how long a legacy effect of cover cropping will remain in the soil. We found that cover crops attenuate negative effects on soil structure that come from soil cultivation. The combination of plants with different litter qualities and rhizodeposits in biodiverse cover crop mixtures can improve the positive effects of cover cropping on soil structure amelioration.
Che-Jen Hsiao, Pedro A. M. Leite, Ayumi Hyodo, and Thomas W. Boutton
SOIL, 10, 93–108, https://doi.org/10.5194/soil-10-93-2024, https://doi.org/10.5194/soil-10-93-2024, 2024
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Tree cover has increased in grasslands worldwide, with juniper and oak trees expanding in the southern Great Plains, USA. Here, we examine how these changes interact with geology to affect soil C, N, and P storage. Soil concentrations of these elements were significantly higher under trees than grasslands but increased more under trees growing on Edwards soils. Our results suggest that geology and vegetation change should be considered when predicting soil storage in dryland ecosystems globally.
David S. McLagan, Carina Esser, Lorenz Schwab, Jan G. Wiederhold, Jan-Helge Richard, and Harald Biester
SOIL, 10, 77–92, https://doi.org/10.5194/soil-10-77-2024, https://doi.org/10.5194/soil-10-77-2024, 2024
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Sorption of mercury in soils, aquifer materials, and sediments is primarily linked to organic matter. Using column experiments, mercury concentration, speciation, and stable isotope analyses, we show that large quantities of mercury in soil water and groundwater can be sorbed to inorganic minerals; sorption to the solid phase favours lighter isotopes. Data provide important insights on the transport and fate of mercury in soil–groundwater systems and particularly in low-organic-matter systems.
Marketa Stepanova, Martin Novak, Bohuslava Cejkova, Ivana Jackova, Frantisek Buzek, Frantisek Veselovsky, Jan Curik, Eva Prechova, Arnost Komarek, and Leona Bohdalkova
SOIL, 9, 623–640, https://doi.org/10.5194/soil-9-623-2023, https://doi.org/10.5194/soil-9-623-2023, 2023
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Biological N2 fixation helps to sustain carbon accumulation in peatlands and to remove CO2 from the atmosphere. Changes in N2 fixation may affect the dynamics of global change. Increasing inputs of reactive N from air pollution should lead to downregulation of N2 fixation. Data from three N-polluted peat bogs show an interplay of N2-fixation rates with 10 potential drivers of this process. N2 fixation was measurable only at one site characterized by high phosphorus and low sulfate availability.
Tatjana C. Speckert, Jeannine Suremann, Konstantin Gavazov, Maria J. Santos, Frank Hagedorn, and Guido L. B. Wiesenberg
SOIL, 9, 609–621, https://doi.org/10.5194/soil-9-609-2023, https://doi.org/10.5194/soil-9-609-2023, 2023
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Soil organic carbon (SOC) is key player in the global carbon cycle. Afforestation on pastures potentially alters organic matter input and SOC sequestration. We investigated the effects of a Picea abies L. afforestation sequence (0 to 130 years) on a former subalpine pasture on SOC stocks and dynamics. We found no difference in the SOC stock after 130 years of afforestation and thus no additional SOC sequestration. SOC composition was altered due to a modified SOC input following afforestation.
Sam J. Leuthold, Jocelyn M. Lavallee, Bruno Basso, William F. Brinton, and M. Francesca Cotrufo
EGUsphere, https://doi.org/10.5194/egusphere-2023-2327, https://doi.org/10.5194/egusphere-2023-2327, 2023
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We examined physical soil organic matter fractions to understand their relationship to temporal variability in crop yield at the field scale. We found that interactions between crop productivity, topography, and climate led to variability in soil organic matter stocks among different yield stability zones. Our results imply linkages between soil organic matter and yield stability may be scale-dependent, and that particulate organic matter may be an indicator of unstable areas within croplands.
Lauren M. Gillespie, Nathalie Y. Triches, Diego Abalos, Peter Finke, Sophie Zechmeister-Boltenstern, Stephan Glatzel, and Eugenio Díaz-Pinés
SOIL, 9, 517–531, https://doi.org/10.5194/soil-9-517-2023, https://doi.org/10.5194/soil-9-517-2023, 2023
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Forest soil is potentially an important source or sink of greenhouse gases (CO2, N2O, and CH4), but this is affected by soil conditions. We studied how land inclination and soil/litter properties influence the flux of these gases. CO2 and N2O were more affected by inclination than CH4; all were affected by soil/litter properties. This study underlines the importance of inclination and soil/litter properties in predicting greenhouse gas fluxes from forest soil and potential source–sink balance.
Sastrika Anindita, Peter Finke, and Steven Sleutel
SOIL, 9, 443–459, https://doi.org/10.5194/soil-9-443-2023, https://doi.org/10.5194/soil-9-443-2023, 2023
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This study investigated how land use, through its impact on soil geochemistry, might indirectly control soil organic carbon (SOC) content in tropical volcanic soils in Indonesia. We analyzed SOC fractions, substrate-specific mineralization, and net priming of SOC. Our results indicated that the enhanced formation of aluminum (hydr)oxides promoted aggregation and physical occlusion of OC, which is consistent with the lesser degradability of SOC in agricultural soils.
Amicie A. Delahaie, Pierre Barré, François Baudin, Dominique Arrouays, Antonio Bispo, Line Boulonne, Claire Chenu, Claudy Jolivet, Manuel P. Martin, Céline Ratié, Nicolas P. A. Saby, Florence Savignac, and Lauric Cécillon
SOIL, 9, 209–229, https://doi.org/10.5194/soil-9-209-2023, https://doi.org/10.5194/soil-9-209-2023, 2023
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We characterized organic matter in French soils by analysing samples from the French RMQS network using Rock-Eval thermal analysis. We found that thermal analysis is appropriate to characterize large set of samples (ca. 2000) and provides interpretation references for Rock-Eval parameter values. This shows that organic matter in managed soils is on average more oxidized and more thermally stable and that some Rock-Eval parameters are good proxies for organic matter biogeochemical stability.
Britta Greenshields, Barbara von der Lühe, Harold J. Hughes, Christian Stiegler, Suria Tarigan, Aiyen Tjoa, and Daniela Sauer
SOIL, 9, 169–188, https://doi.org/10.5194/soil-9-169-2023, https://doi.org/10.5194/soil-9-169-2023, 2023
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Silicon (Si) research could provide complementary measures in sustainably cultivating oil-palm monocultures. Our study shows that current oil-palm management practices and topsoil erosion on oil-palm plantations in Indonesia have caused a spatial distribution of essential Si pools in soil. A lack of well-balanced Si levels in topsoil could negatively affect crop yield and soil fertility for future replanting at the same plantation site. Potential measures are suggested to maintain Si cycling.
Kenji Fujisaki, Tiphaine Chevallier, Antonio Bispo, Jean-Baptiste Laurent, François Thevenin, Lydie Chapuis-Lardy, Rémi Cardinael, Christine Le Bas, Vincent Freycon, Fabrice Bénédet, Vincent Blanfort, Michel Brossard, Marie Tella, and Julien Demenois
SOIL, 9, 89–100, https://doi.org/10.5194/soil-9-89-2023, https://doi.org/10.5194/soil-9-89-2023, 2023
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This paper presents a first comprehensive thesaurus for management practices driving soil organic carbon (SOC) storage. So far, a comprehensive thesaurus of management practices in agriculture and forestry has been lacking. It will help to merge datasets, a promising way to evaluate the impacts of management practices in agriculture and forestry on SOC. Identifying the drivers of SOC stock changes is of utmost importance to contribute to global challenges (climate change, food security).
Oliver van Straaten, Larissa Kulp, Guntars O. Martinson, Dan Paul Zederer, and Ulrike Talkner
SOIL, 9, 39–54, https://doi.org/10.5194/soil-9-39-2023, https://doi.org/10.5194/soil-9-39-2023, 2023
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Across northern Europe, millions of hectares of forest have been limed to counteract soil acidification and restore forest ecosystems. In this study, we investigated how restorative liming affects the forest soil organic carbon (SOC) stocks and correspondingly ecosystem greenhouse gas fluxes. We found that the magnitude and direction of SOC stock changes hinge on the inherent site characteristics, namely, forest type, soil texture, initial soil pH, and initial soil SOC stocks (before liming).
Junxiao Pan, Jinsong Wang, Dashuan Tian, Ruiyang Zhang, Yang Li, Lei Song, Jiaming Yang, Chunxue Wei, and Shuli Niu
SOIL, 8, 687–698, https://doi.org/10.5194/soil-8-687-2022, https://doi.org/10.5194/soil-8-687-2022, 2022
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We found that climatic, edaphic, plant and microbial variables jointly affect soil inorganic carbon (SIC) stock in Tibetan grasslands, and biotic factors have a larger contribution than abiotic factors to the variation in SIC stock. The effects of microbial and plant variables on SIC stock weakened with soil depth, while the effects of edaphic variables strengthened. The contrasting responses and drivers of SIC stock highlight differential mechanisms underlying SIC preservation with soil depth.
Yifeng Zhang, Sen Dou, Batande Sinovuyo Ndzelu, Rui Ma, Dandan Zhang, Xiaowei Zhang, Shufen Ye, and Hongrui Wang
SOIL, 8, 605–619, https://doi.org/10.5194/soil-8-605-2022, https://doi.org/10.5194/soil-8-605-2022, 2022
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How to effectively convert corn straw into humic substances and return them to the soil in a relatively stable form is a concerning topic. Through a 360 d field experiment under equal carbon (C) mass, we found that return of the fermented corn straw treated with Trichoderma reesei to the field is more valuable and conducive to increasing easily oxidizable organic C, humus C content, and carbon pool management index than the direct application of corn straw.
Ling Mao, Shaoming Ye, and Shengqiang Wang
SOIL, 8, 487–505, https://doi.org/10.5194/soil-8-487-2022, https://doi.org/10.5194/soil-8-487-2022, 2022
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Soil ecological stoichiometry offers a tool to explore the distribution, cycling, limitation, and balance of chemical elements. This study improved the understanding of soil organic carbon and nutrient dynamics in tea plantation ecosystems and also provided supplementary information for soil ecological stoichiometry in global terrestrial ecosystems.
Steffen Schlüter, Tim Roussety, Lena Rohe, Vusal Guliyev, Evgenia Blagodatskaya, and Thomas Reitz
SOIL, 8, 253–267, https://doi.org/10.5194/soil-8-253-2022, https://doi.org/10.5194/soil-8-253-2022, 2022
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We combined microstructure analysis via X-ray CT with carbon mineralization analysis via respirometry of intact soil cores from different land uses. We found that the amount of particulate organic matter (POM) exerted a dominant control on carbon mineralization in well-aerated topsoils, whereas soil moisture and macroporosity did not play role. This is because carbon mineralization mainly occurs in microbial hotspots around degrading POM, where it is decoupled from conditions of the bulk soil.
Roberta Pulcher, Enrico Balugani, Maurizio Ventura, Nicolas Greggio, and Diego Marazza
SOIL, 8, 199–211, https://doi.org/10.5194/soil-8-199-2022, https://doi.org/10.5194/soil-8-199-2022, 2022
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Biochar, a solid product from the thermal conversion of biomass, can be used as a climate change mitigation strategy, since it can sequester carbon from the atmosphere and store it in the soil. The aim of this study is to assess the potential of biochar as a mitigation strategy in the long term, by modelling the results obtained from an 8-year field experiment. As far as we know, this is the first time that a model for biochar degradation has been validated with long-term field data.
Daniel Rath, Nathaniel Bogie, Leonardo Deiss, Sanjai J. Parikh, Daoyuan Wang, Samantha Ying, Nicole Tautges, Asmeret Asefaw Berhe, Teamrat A. Ghezzehei, and Kate M. Scow
SOIL, 8, 59–83, https://doi.org/10.5194/soil-8-59-2022, https://doi.org/10.5194/soil-8-59-2022, 2022
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Storing C in subsoils can help mitigate climate change, but this requires a better understanding of subsoil C dynamics. We investigated changes in subsoil C storage under a combination of compost, cover crops (WCC), and mineral fertilizer and found that systems with compost + WCC had ~19 Mg/ha more C after 25 years. This increase was attributed to increased transport of soluble C and nutrients via WCC root pores and demonstrates the potential for subsoil C storage in tilled agricultural systems.
Zuzana Frkova, Chiara Pistocchi, Yuliya Vystavna, Katerina Capkova, Jiri Dolezal, and Federica Tamburini
SOIL, 8, 1–15, https://doi.org/10.5194/soil-8-1-2022, https://doi.org/10.5194/soil-8-1-2022, 2022
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Phosphorus (P) is essential for life. We studied microbial processes driving the P cycle in soils developed on the same rock but with different ages (0–100 years) in a cold desert. Compared to previous studies under cold climate, we found much slower weathering of P-containing minerals of soil development, likely due to aridity. However, microbes dominate short-term dynamics and progressively redistribute P from the rock into more available forms, making it available for plants at later stages.
Carrie L. Thomas, Boris Jansen, E. Emiel van Loon, and Guido L. B. Wiesenberg
SOIL, 7, 785–809, https://doi.org/10.5194/soil-7-785-2021, https://doi.org/10.5194/soil-7-785-2021, 2021
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Plant organs, such as leaves, contain a variety of chemicals that are eventually deposited into soil and can be useful for studying organic carbon cycling. We performed a systematic review of available data of one type of plant-derived chemical, n-alkanes, to determine patterns of degradation or preservation from the source plant to the soil. We found that while there was degradation in the amount of n-alkanes from plant to soil, some aspects of the chemical signature were preserved.
Benjamin Bukombe, Peter Fiener, Alison M. Hoyt, Laurent K. Kidinda, and Sebastian Doetterl
SOIL, 7, 639–659, https://doi.org/10.5194/soil-7-639-2021, https://doi.org/10.5194/soil-7-639-2021, 2021
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Through a laboratory incubation experiment, we investigated the spatial patterns of specific maximum heterotrophic respiration in tropical African mountain forest soils developed from contrasting parent material along slope gradients. We found distinct differences in soil respiration between soil depths and geochemical regions related to soil fertility and the chemistry of the soil solution. The topographic origin of our samples was not a major determinant of the observed rates of respiration.
Patricia Merdy, Yves Lucas, Bruno Coulomb, Adolpho J. Melfi, and Célia R. Montes
SOIL, 7, 585–594, https://doi.org/10.5194/soil-7-585-2021, https://doi.org/10.5194/soil-7-585-2021, 2021
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Transfer of organic C from topsoil to deeper horizons and the water table is little documented, especially in equatorial environments, despite high primary productivity in the evergreen forest. Using column experiments with podzol soil and a percolating solution sampled in an Amazonian podzol area, we show how the C-rich Bh horizon plays a role in natural organic matter transfer and Si, Fe and Al mobility after a kaolinitic layer transition, thus giving insight to the genesis of tropical podzol.
Jörg Schnecker, D. Boone Meeden, Francisco Calderon, Michel Cavigelli, R. Michael Lehman, Lisa K. Tiemann, and A. Stuart Grandy
SOIL, 7, 547–561, https://doi.org/10.5194/soil-7-547-2021, https://doi.org/10.5194/soil-7-547-2021, 2021
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Drought and flooding challenge agricultural systems and their management globally. Here we investigated the response of soils from long-term agricultural field sites with simple and diverse crop rotations to either drought or flooding. We found that irrespective of crop rotation complexity, soil and microbial properties were more resistant to flooding than to drought and highly resilient to drought and flooding during single or repeated stress pulses.
Mario Reichenbach, Peter Fiener, Gina Garland, Marco Griepentrog, Johan Six, and Sebastian Doetterl
SOIL, 7, 453–475, https://doi.org/10.5194/soil-7-453-2021, https://doi.org/10.5194/soil-7-453-2021, 2021
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In deeply weathered tropical rainforest soils of Africa, we found that patterns of soil organic carbon stocks differ between soils developed from geochemically contrasting parent material due to differences in the abundance of organo-mineral complexes, the presence/absence of chemical stabilization mechanisms of carbon with minerals and the presence of fossil organic carbon from sedimentary rocks. Physical stabilization mechanisms by aggregation provide additional protection of soil carbon.
Fabian Kalks, Gabriel Noren, Carsten W. Mueller, Mirjam Helfrich, Janet Rethemeyer, and Axel Don
SOIL, 7, 347–362, https://doi.org/10.5194/soil-7-347-2021, https://doi.org/10.5194/soil-7-347-2021, 2021
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Sedimentary rocks contain organic carbon that may end up as soil carbon. However, this source of soil carbon is overlooked and has not been quantified sufficiently. We analysed 10 m long sediment cores with three different sedimentary rocks. All sediments contain considerable amounts of geogenic carbon contributing 3 %–12 % to the total soil carbon below 30 cm depth. The low 14C content of geogenic carbon can result in underestimations of soil carbon turnover derived from 14C data.
Maximilian Kirsten, Robert Mikutta, Didas N. Kimaro, Karl-Heinz Feger, and Karsten Kalbitz
SOIL, 7, 363–375, https://doi.org/10.5194/soil-7-363-2021, https://doi.org/10.5194/soil-7-363-2021, 2021
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Mineralogical combinations of aluminous clay and pedogenic Fe oxides revealed significant effects on soil structure and related organic carbon (OC) storage.
The mineralogical combination resulting in the largest aggregate stability does not better preserve OC during conversion of forests into croplands.
Structural changes in the direction of smaller mean weight diameters do not cancel out the stabilizing effect of soil minerals.
Sophie F. von Fromm, Alison M. Hoyt, Markus Lange, Gifty E. Acquah, Ermias Aynekulu, Asmeret Asefaw Berhe, Stephan M. Haefele, Steve P. McGrath, Keith D. Shepherd, Andrew M. Sila, Johan Six, Erick K. Towett, Susan E. Trumbore, Tor-G. Vågen, Elvis Weullow, Leigh A. Winowiecki, and Sebastian Doetterl
SOIL, 7, 305–332, https://doi.org/10.5194/soil-7-305-2021, https://doi.org/10.5194/soil-7-305-2021, 2021
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We investigated various soil and climate properties that influence soil organic carbon (SOC) concentrations in sub-Saharan Africa. Our findings indicate that climate and geochemistry are equally important for explaining SOC variations. The key SOC-controlling factors are broadly similar to those for temperate regions, despite differences in soil development history between the two regions.
Claudia Cagnarini, Stephen Lofts, Luigi Paolo D'Acqui, Jochen Mayer, Roman Grüter, Susan Tandy, Rainer Schulin, Benjamin Costerousse, Simone Orlandini, and Giancarlo Renella
SOIL, 7, 107–123, https://doi.org/10.5194/soil-7-107-2021, https://doi.org/10.5194/soil-7-107-2021, 2021
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Application of organic amendments, although considered a sustainable form of soil fertilisation, may cause an accumulation of trace elements (TEs) in the topsoil. In this research, we analysed the concentration of zinc, copper, lead and cadmium in a > 60-year experiment in Switzerland and showed that the dynamic model IDMM adequately predicted the historical TE concentrations in plots amended with farmyard manure, sewage sludge and compost and produced reasonable concentration trends up to 2100.
Simon Baumgartner, Marijn Bauters, Matti Barthel, Travis W. Drake, Landry C. Ntaboba, Basile M. Bazirake, Johan Six, Pascal Boeckx, and Kristof Van Oost
SOIL, 7, 83–94, https://doi.org/10.5194/soil-7-83-2021, https://doi.org/10.5194/soil-7-83-2021, 2021
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We compared stable isotope signatures of soil profiles in different forest ecosystems within the Congo Basin to assess ecosystem-level differences in N cycling, and we examined the local effect of topography on the isotopic signature of soil N. Soil δ15N profiles indicated that the N cycling in in the montane forest is more closed, whereas the lowland forest and Miombo woodland experienced a more open N cycle. Topography only alters soil δ15N values in forests with high erosional forces.
Rota Wagai, Masako Kajiura, and Maki Asano
SOIL, 6, 597–627, https://doi.org/10.5194/soil-6-597-2020, https://doi.org/10.5194/soil-6-597-2020, 2020
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Global significance of metals (extractable Fe and Al phases) to control organic matter (OM) in recognized. Next key questions include the identification of their localization and mechanism behind OM–metal relationships. Across 23 soils of contrasting mineralogy, Fe and Al phases were mainly associated with microbially processed OM as meso-density microaggregates. OM- and metal-rich nanocomposites with a narrow OM : metal ratio likely acted as binding agents. A new conceptual model was proposed.
Marco Panettieri, Denis Courtier-Murias, Cornelia Rumpel, Marie-France Dignac, Gonzalo Almendros, and Abad Chabbi
SOIL, 6, 435–451, https://doi.org/10.5194/soil-6-435-2020, https://doi.org/10.5194/soil-6-435-2020, 2020
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In the context of global change, soil has been identified as a potential C sink, depending on land-use strategies. This work is devoted to identifying the processes affecting labile soil C pools resulting from changes in land use. We show that the land-use change in ley grassland provoked a decoupling of the storage and degradation processes after the grassland phase. Overall, the study enables us to develop a sufficient understanding of fine-scale C dynamics to refine soil C prediction models.
Miriam Groß-Schmölders, Pascal von Sengbusch, Jan Paul Krüger, Kristy Klein, Axel Birkholz, Jens Leifeld, and Christine Alewell
SOIL, 6, 299–313, https://doi.org/10.5194/soil-6-299-2020, https://doi.org/10.5194/soil-6-299-2020, 2020
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Degradation turns peatlands into a source of CO2. There is no cost- or time-efficient method available for indicating peatland hydrology or the success of restoration. We found that 15N values have a clear link to microbial communities and degradation. We identified trends in natural, drained and rewetted conditions and concluded that 15N depth profiles can act as a reliable and efficient tool for obtaining information on current hydrology, restoration success and drainage history.
Martin Erlandsson Lampa, Harald U. Sverdrup, Kevin H. Bishop, Salim Belyazid, Ali Ameli, and Stephan J. Köhler
SOIL, 6, 231–244, https://doi.org/10.5194/soil-6-231-2020, https://doi.org/10.5194/soil-6-231-2020, 2020
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In this study, we demonstrate how new equations describing base cation release from mineral weathering can reproduce patterns in observations from stream and soil water. This is a major step towards modeling base cation cycling on the catchment scale, which would be valuable for defining the highest sustainable rates of forest harvest and levels of acidifying deposition.
Benjamin Andrieux, David Paré, Julien Beguin, Pierre Grondin, and Yves Bergeron
SOIL, 6, 195–213, https://doi.org/10.5194/soil-6-195-2020, https://doi.org/10.5194/soil-6-195-2020, 2020
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Our study aimed to disentangle the contribution of several drivers to explaining the proportion of soil carbon that can be released to CO2 through microbial respiration. We found that boreal-forest soil chemistry is an important driver of the amount of carbon that microbes can process. Our results emphasize the need to include the effects of soil chemistry into models of carbon cycling to better anticipate the role played by boreal-forest soils in carbon-cycle–climate feedbacks.
Jonathan Sanderman and A. Stuart Grandy
SOIL, 6, 131–144, https://doi.org/10.5194/soil-6-131-2020, https://doi.org/10.5194/soil-6-131-2020, 2020
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Soils contain one of the largest and most dynamic pools of carbon on Earth, yet scientists still struggle to understand the reactivity and fate of soil organic matter upon disturbance. In this study, we found that with increasing thermal stability, the turnover time of organic matter increased from decades to centuries with a concurrent shift in chemical composition. In this proof-of-concept study, we found that ramped thermal analyses can provide new insights for understanding soil carbon.
Carlos Alberto Quesada, Claudia Paz, Erick Oblitas Mendoza, Oliver Lawrence Phillips, Gustavo Saiz, and Jon Lloyd
SOIL, 6, 53–88, https://doi.org/10.5194/soil-6-53-2020, https://doi.org/10.5194/soil-6-53-2020, 2020
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Amazon soils hold as much carbon (C) as is contained in the vegetation. In this work we sampled soils across 8 different Amazonian countries to try to understand which soil properties control current Amazonian soil C concentrations. We confirm previous knowledge that highly developed soils hold C through clay content interactions but also show a previously unreported mechanism of soil C stabilization in the younger Amazonian soil types which hold C through aluminium organic matter interactions.
Songyu Yang, Boris Jansen, Samira Absalah, Rutger L. van Hall, Karsten Kalbitz, and Erik L. H. Cammeraat
SOIL, 6, 1–15, https://doi.org/10.5194/soil-6-1-2020, https://doi.org/10.5194/soil-6-1-2020, 2020
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Soils store large carbon and are important for global warming. We do not know what factors are important for soil carbon storage in the alpine Andes or how they work. We studied how rainfall affects soil carbon storage related to soil structure. We found soil structure is not important, but soil carbon storage and stability controlled by rainfall is dependent on rocks under the soils. The results indicate that we should pay attention to the rocks when we study soil carbon storage in the Andes.
Samuel Bouchoms, Zhengang Wang, Veerle Vanacker, and Kristof Van Oost
SOIL, 5, 367–382, https://doi.org/10.5194/soil-5-367-2019, https://doi.org/10.5194/soil-5-367-2019, 2019
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Soil erosion has detrimental effects on soil fertility which can reduce carbon inputs coming from crops to soils. Our study integrated this effect into a model linking soil organic carbon (SOC) dynamics to erosion and crop productivity. When compared to observations, the inclusion of productivity improved SOC loss predictions. Over centuries, ignoring crop productivity evolution in models could result in underestimating SOC loss and overestimating C exchanged with the atmosphere.
Nicholas P. Rosenstock, Johan Stendahl, Gregory van der Heijden, Lars Lundin, Eric McGivney, Kevin Bishop, and Stefan Löfgren
SOIL, 5, 351–366, https://doi.org/10.5194/soil-5-351-2019, https://doi.org/10.5194/soil-5-351-2019, 2019
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Biofuel harvests from forests involve large removals of available nutrients, necessitating accurate measurements of soil nutrient stocks. We found that dilute hydrochloric acid extractions from soils released far more Ca, Na, and K than classical salt–extracted exchangeable nutrient pools. The size of these acid–extractable pools may indicate that forest ecosystems could sustain greater biomass extractions of Ca, Mg, and K than are predicted from salt–extracted exchangeable base cation pools.
Tiphaine Chevallier, Kenji Fujisaki, Olivier Roupsard, Florian Guidat, Rintaro Kinoshita, Elias de Melo Viginio Filho, Peter Lehner, and Alain Albrecht
SOIL, 5, 315–332, https://doi.org/10.5194/soil-5-315-2019, https://doi.org/10.5194/soil-5-315-2019, 2019
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Soil organic carbon (SOC) is the largest terrestrial C stock. Andosols of volcanic areas hold particularly large stocks (e.g. from 24 to 72 kgC m−2 in the upper 2 m of soil) as determined via MIR spectrometry at our Costa Rican study site: a 1 km2 basin covered by coffee agroforestry. Andic soil properties explained this high variability, which did not correlate with stocks in the upper 20 cm of soil. Topography and pedogenesis are needed to understand the SOC stocks at landscape scales.
Katelyn A. Congreves, Trang Phan, and Richard E. Farrell
SOIL, 5, 265–274, https://doi.org/10.5194/soil-5-265-2019, https://doi.org/10.5194/soil-5-265-2019, 2019
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There are surprising grey areas in the precise quantification of pathways that produce nitrous oxide, a potent greenhouse gas, as influenced by soil moisture. Here, we take a new look at a classic study but use isotopomers as a powerful tool to determine the source pathways of nitrous oxide as regulated by soil moisture. Our results support earlier research, but we contribute scientific advancements by providing models that enable quantifying source partitioning rather than just inferencing.
Eric McGivney, Jon Petter Gustafsson, Salim Belyazid, Therese Zetterberg, and Stefan Löfgren
SOIL, 5, 63–77, https://doi.org/10.5194/soil-5-63-2019, https://doi.org/10.5194/soil-5-63-2019, 2019
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Forest management may lead to long-term soil acidification due to the removal of base cations during harvest. By means of the HD-MINTEQ model, we compared the acidification effects of harvesting with the effects of historical acid rain at three forested sites in Sweden. The effects of harvesting on pH were predicted to be much smaller than those resulting from acid deposition during the 20th century. There were only very small changes in predicted weathering rates due to acid rain or harvest.
Veronika Kronnäs, Cecilia Akselsson, and Salim Belyazid
SOIL, 5, 33–47, https://doi.org/10.5194/soil-5-33-2019, https://doi.org/10.5194/soil-5-33-2019, 2019
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Weathering rates in forest soils are important for sustainable forestry but cannot be measured. In this paper, we have modelled weathering with the commonly used PROFILE model as well as with the dynamic model ForSAFE, better suited to a changing climate with changing human activities but never before tested for weathering calculations. We show that ForSAFE gives comparable weathering rates to PROFILE and that it shows the variation in weathering with time and works well for scenario modelling.
Jon Petter Gustafsson, Salim Belyazid, Eric McGivney, and Stefan Löfgren
SOIL, 4, 237–250, https://doi.org/10.5194/soil-4-237-2018, https://doi.org/10.5194/soil-4-237-2018, 2018
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This paper investigates how different dynamic soil chemistry models describe the processes governing aluminium and base cations in acid soil waters. We find that traditional cation-exchange equations, which are still used in many models, diverge from state-of-the-art complexation submodels such as WHAM, SHM, and NICA-Donnan when large fluctuations in pH or ionic strength occur. In conclusion, the complexation models provide a better basis for the modelling of chemical dynamics in acid soils.
Talal Darwish, Thérèse Atallah, and Ali Fadel
SOIL, 4, 225–235, https://doi.org/10.5194/soil-4-225-2018, https://doi.org/10.5194/soil-4-225-2018, 2018
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This paper is part of the GSP-ITPS effort to produce a global SOC map and update information on C stocks using old and new soil information to assess the potential for enhanced C sequestration in dry land areas of the NENA region. We used the DSMW from FAO-UNESCO (2007), focusing on organic and inorganic content in 0.3 m of topsoil and 0.7 m of subsoil, to discuss the human factors affecting the accumulation of organic C and the fate of inorganic C.
Juhwan Lee, Gina M. Garland, and Raphael A. Viscarra Rossel
SOIL, 4, 213–224, https://doi.org/10.5194/soil-4-213-2018, https://doi.org/10.5194/soil-4-213-2018, 2018
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Soil nitrogen (N) is an essential element for plant growth, but its plant-available forms are subject to loss from the environment by leaching and gaseous emissions. Still, factors controlling soil mineral N concentrations at large spatial scales are not well understood. We determined and discussed primary soil controls over the concentrations of NH4+ and NO3− at the continental scale of Australia while considering specific dominant land use patterns on a regional basis.
Eleanor Ursula Hobley, Brian Murphy, and Aaron Simmons
SOIL, 4, 169–171, https://doi.org/10.5194/soil-4-169-2018, https://doi.org/10.5194/soil-4-169-2018, 2018
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This research evaluates equations to calculate soil organic carbon (SOC) stocks. Although various equations exist for SOC stock calculations, we recommend using the simplest equation with THE lowest associated errors. Adjusting SOC stock calculations for rock content is essential. Using the mass proportion of rocks to do so minimizes error.
Cora Vos, Angélica Jaconi, Anna Jacobs, and Axel Don
SOIL, 4, 153–167, https://doi.org/10.5194/soil-4-153-2018, https://doi.org/10.5194/soil-4-153-2018, 2018
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Soil organic carbon sequestration can be facilitated by agricultural management, but its influence is not the same on all soil carbon pools. We assessed how soil organic carbon is distributed among C pools in Germany, identified factors influencing this distribution and identified regions with high vulnerability to C losses. Explanatory variables were soil texture, C / N ratio, soil C content and pH. For some regions, the drivers were linked to the land-use history as heathlands or peatlands.
Sebastian Rainer Fiedler, Jürgen Augustin, Nicole Wrage-Mönnig, Gerald Jurasinski, Bertram Gusovius, and Stephan Glatzel
SOIL, 3, 161–176, https://doi.org/10.5194/soil-3-161-2017, https://doi.org/10.5194/soil-3-161-2017, 2017
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Injection of biogas digestates (BDs) is suspected to increase losses of N2O and thus to counterbalance prevented NH3 emissions. We determined N2O and N2 losses after mixing high concentrations of BD into two soils by an incubation under an artificial helium–oxygen atmosphere. Emissions did not increase with the application rate of BD, probably due to an inhibitory effect of the high NH4+ content in BD on nitrification. However, cumulated gaseous N losses may effectively offset NH3 reductions.
Ranae Dietzel, Matt Liebman, and Sotirios Archontoulis
SOIL, 3, 139–152, https://doi.org/10.5194/soil-3-139-2017, https://doi.org/10.5194/soil-3-139-2017, 2017
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Roots deeper in the soil are made up of more carbon and less nitrogen compared to roots at shallower depths, which may help explain deep-carbon origin. A comparison of prairie and maize rooting systems showed that in moving from prairie to maize, a large, structural-tissue-dominated root carbon pool with slow turnover concentrated at shallow depths was replaced by a small, nonstructural-tissue-dominated root carbon pool with fast turnover evenly distributed in the soil profile.
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Executive editor
This manuscript is published as SOIL Letters publication as it provides a timely and important contribution, formulating six fundamental principles for the robust study of soil carbon saturation. This is an important topic in research on soil carbon and its role in climate change mitigation which should be of interest to the wider geoscience community.
This manuscript is published as SOIL Letters publication as it provides a timely and important...
Short summary
Soil C saturation has been tested in several recent studies and led to a debate about its existence. We argue that, to test C saturation, one should pay attention to six fundamental principles: the right measures, the right units, the right dispersive energy and application, the right soil type, the right clay type, and the right saturation level. Once we take care of those six rights across studies, we find support for a maximum of C stabilized by minerals and thus soil C saturation.
Soil C saturation has been tested in several recent studies and led to a debate about its...
