Articles | Volume 9, issue 1
https://doi.org/10.5194/soil-9-301-2023
© Author(s) 2023. 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-9-301-2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Managing soil organic carbon in tropical agroecosystems: evidence from four long-term experiments in Kenya
Department of Environmental Systems Science, ETH Zurich, 8092 Zurich, Switzerland
Marc Corbeels
CIRAD, Avenue d'Agropolis, 34398 Montpellier, France
International Institute of Tropical Agriculture (IITA), c/o ICIPE Compound, P.O. Box 30772-00100, Nairobi, Kenya
Antoine Couëdel
CIRAD, Avenue d'Agropolis, 34398 Montpellier, France
Samuel Mathu Ndungu
International Institute of Tropical Agriculture (IITA), c/o ICIPE Compound, P.O. Box 30772-00100, Nairobi, Kenya
Monicah Wanjiku Mucheru-Muna
Department of Environmental Sciences and Education, Kenyatta University, P.O. Box 43844-00100, Nairobi, Kenya
Daniel Mugendi
Department of Land and Water Management, University of Embu, P.O. Box 6-60100, Embu, Kenya
Magdalena Necpalova
Department of Environmental Systems Science, ETH Zurich, 8092 Zurich, Switzerland
School of Agriculture and Food Science, University College Dublin, Dublin, Ireland
Wycliffe Waswa
International Institute of Tropical Agriculture (IITA), c/o ICIPE Compound, P.O. Box 30772-00100, Nairobi, Kenya
Marijn Van de Broek
Department of Environmental Systems Science, ETH Zurich, 8092 Zurich, Switzerland
Bernard Vanlauwe
International Institute of Tropical Agriculture (IITA), c/o ICIPE Compound, P.O. Box 30772-00100, Nairobi, Kenya
Johan Six
Department of Environmental Systems Science, ETH Zurich, 8092 Zurich, Switzerland
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Marijn Van de Broek, Fiona Stewart-Smith, Moritz Laub, Marc Corbeels, Monicah Wanjiku Mucheru-Muna, Daniel Mugendi, Wycliffe Waswa, Bernard Vanlauwe, and Johan Six
EGUsphere, https://doi.org/10.5194/egusphere-2025-2287, https://doi.org/10.5194/egusphere-2025-2287, 2025
This preprint is open for discussion and under review for SOIL (SOIL).
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To improve soil health and increase crop yields, organic matter is commenly added to arable soils. Studying the effect of different organic amenmends on soil organic carbon sequestration in four long-term field trials in Kenya, we found that only a small portion (< 7 %) of added carbon was stabilised. Moreover, this was only observed in the top 15 cm of the soil. These results underline the challenges associated with increasing the organic carbon content of tropical arable soils.
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
Biogeosciences, 21, 3691–3716, https://doi.org/10.5194/bg-21-3691-2024, https://doi.org/10.5194/bg-21-3691-2024, 2024
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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 adjustments, DayCent represented measured mean yields and soil carbon stock changes well and N2O emissions acceptably. Our results showed that soil fertility losses could be reduced but not completely eliminated with ISFM and that, while N2O emissions increased with ISFM, emissions per kilogram yield decreased.
Johan Six, Sebastian Doetterl, Moritz Laub, Claude R. Müller, and Marijn Van de Broek
SOIL, 10, 275–279, https://doi.org/10.5194/soil-10-275-2024, https://doi.org/10.5194/soil-10-275-2024, 2024
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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.
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.
Laura Summerauer, Fernando Bamba, Bendicto Akoraebirungi, Ahurra Wobusobozi, Marijn Bauters, Travis William Drake, Negar Haghipour, Clovis Kabaseke, Daniel Muhindo Iragi, Landry Cizungu Ntaboba, Leonardo Ramirez-Lopez, Johan Six, Daniel Wasner, and Sebastian Doetterl
EGUsphere, https://doi.org/10.5194/egusphere-2025-4625, https://doi.org/10.5194/egusphere-2025-4625, 2025
This preprint is open for discussion and under review for Biogeosciences (BG).
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Deforestation for croplands on tropical hillslopes causes severe soil degradation and loss of fertile topsoil. We found that this leads to a steep decline in soil fertility, including organic carbon, nitrogen, and phosphorus. This makes the land unproductive, often leading farmers to abandon it. Replanting with Eucalyptus trees doesn't restore fertility. This degradation leads to cropland lifespans of only 100–170 years and poses a serious threat to future food production.
Antoine de Clippele, Astrid C. H. Jaeger, Simon Baumgartner, Marijn Bauters, Pascal Boeckx, Clement Botefa, Glenn Bush, Jessica Carilli, Travis W. Drake, Christian Ekamba, Gode Lompoko, Nivens Bey Mukwiele, Kristof Van Oost, Roland A. Werner, Joseph Zambo, Johan Six, and Matti Barthel
Biogeosciences, 22, 3011–3027, https://doi.org/10.5194/bg-22-3011-2025, https://doi.org/10.5194/bg-22-3011-2025, 2025
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Tropical forest soils as a large terrestrial source of carbon dioxide (CO2) contribute to the global greenhouse gas budget. Despite this, carbon flux data from forested wetlands are scarce in tropical Africa. The study presents 3 years of semi-continuous measurements of surface CO2 fluxes within the Congo Basin. Although no seasonal patterns were evident, our results show a positive effect of soil temperature and moisture, while a quadratic relationship was observed with the water table.
Claude Raoul Müller, Johan Six, Daniel Mugendi Njiru, Bernard Vanlauwe, and Marijn Van de Broek
Biogeosciences, 22, 2733–2747, https://doi.org/10.5194/bg-22-2733-2025, https://doi.org/10.5194/bg-22-2733-2025, 2025
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We studied how different organic and inorganic nutrient inputs affect soil organic carbon (SOC) down to 70 cm in Kenya. After 19 years, all organic treatments increased SOC stocks compared with the control, but mineral nitrogen had no significant effect. Manure was the organic treatment that significantly increased SOC at the deepest soil depths, as its effect could be observed down to 60 cm. Manure was the best strategy to limit SOC loss in croplands and maintain soil quality after deforestation.
Marijn Van de Broek, Fiona Stewart-Smith, Moritz Laub, Marc Corbeels, Monicah Wanjiku Mucheru-Muna, Daniel Mugendi, Wycliffe Waswa, Bernard Vanlauwe, and Johan Six
EGUsphere, https://doi.org/10.5194/egusphere-2025-2287, https://doi.org/10.5194/egusphere-2025-2287, 2025
This preprint is open for discussion and under review for SOIL (SOIL).
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To improve soil health and increase crop yields, organic matter is commenly added to arable soils. Studying the effect of different organic amenmends on soil organic carbon sequestration in four long-term field trials in Kenya, we found that only a small portion (< 7 %) of added carbon was stabilised. Moreover, this was only observed in the top 15 cm of the soil. These results underline the challenges associated with increasing the organic carbon content of tropical arable soils.
Roxanne Daelman, Marijn Bauters, Matti Barthel, Emmanuel Bulonza, Lodewijk Lefevre, José Mbifo, Johan Six, Klaus Butterbach-Bahl, Benjamin Wolf, Ralf Kiese, and Pascal Boeckx
Biogeosciences, 22, 1529–1542, https://doi.org/10.5194/bg-22-1529-2025, https://doi.org/10.5194/bg-22-1529-2025, 2025
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The increase in atmospheric concentrations of several greenhouse gases (GHGs) since 1750 is attributed to human activity. However, natural ecosystems, such as tropical forests, also contribute to GHG budgets. The Congo Basin hosts the second largest tropical forest and is understudied. In this study, measurements of soil GHG exchange were carried out during 16 months in a tropical forest in the Congo Basin. Overall, the soil acted as a major source of CO2 and N2O and a minor sink of CH4.
Marijn Van de Broek, Gerard Govers, Marion Schrumpf, and Johan Six
Biogeosciences, 22, 1427–1446, https://doi.org/10.5194/bg-22-1427-2025, https://doi.org/10.5194/bg-22-1427-2025, 2025
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Soil organic carbon models are used to predict how soils affect the concentration of CO2 in the atmosphere. We show that equifinality – the phenomenon that different parameter values lead to correct overall model outputs, albeit with a different model behaviour – is an important source of model uncertainty. Our results imply that adding more complexity to soil organic carbon models is unlikely to lead to better predictions as long as more data to constrain model parameters are not available.
Mosisa Tujuba Wakjira, Nadav Peleg, Johan Six, and Peter Molnar
Hydrol. Earth Syst. Sci., 29, 863–886, https://doi.org/10.5194/hess-29-863-2025, https://doi.org/10.5194/hess-29-863-2025, 2025
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In this study, we implement a climate, water, and crop interaction model to evaluate current conditions and project future changes in rainwater availability and its yield potential, with the goal of informing adaptation policies and strategies in Ethiopia. Although climate change is likely to increase rainfall in Ethiopia, our findings suggest that water-scarce croplands in Ethiopia are expected to face reduced crop yields during the main growing season due to increases in temperature.
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
SOIL, 10, 699–725, https://doi.org/10.5194/soil-10-699-2024, https://doi.org/10.5194/soil-10-699-2024, 2024
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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 the top and subsoil in both the mineral organic matter and particulate organic matter fractions. We also question nitrogen management in these systems.
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
Biogeosciences, 21, 3691–3716, https://doi.org/10.5194/bg-21-3691-2024, https://doi.org/10.5194/bg-21-3691-2024, 2024
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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 adjustments, DayCent represented measured mean yields and soil carbon stock changes well and N2O emissions acceptably. Our results showed that soil fertility losses could be reduced but not completely eliminated with ISFM and that, while N2O emissions increased with ISFM, emissions per kilogram yield decreased.
Claude Raoul Müller, Johan Six, Liesa Brosens, Philipp Baumann, Jean Paolo Gomes Minella, Gerard Govers, and Marijn Van de Broek
SOIL, 10, 349–365, https://doi.org/10.5194/soil-10-349-2024, https://doi.org/10.5194/soil-10-349-2024, 2024
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Subsoils in the tropics are not as extensively studied as those 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.
Johan Six, Sebastian Doetterl, Moritz Laub, Claude R. Müller, and Marijn Van de Broek
SOIL, 10, 275–279, https://doi.org/10.5194/soil-10-275-2024, https://doi.org/10.5194/soil-10-275-2024, 2024
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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.
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
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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.
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.
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.
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.
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.
Cited articles
Adams, A. M., Gillespie, A. W., Dhillon, G. S., Kar, G., Minielly, C., Koala,
S., Ouattara, B., Kimaro, A. A., Bationo, A., Schoenau, J. J., and Peak, D.:
Long-term effects of integrated soil fertility management practices on soil
chemical properties in the Sahel, Geoderma, 366, 114207,
https://doi.org/10.1016/j.geoderma.2020.114207, 2020. a
Anderson, J. M. and Ingram, J. S. I. (Eds.): Tropical Soil Biology and
Fertility: A Handbook of Methods, CAB international, Wallingford,
2nd Edn., https://doi.org/10.2307/2261129, 1993. a
Angst, G., Mueller, K. E., Nierop, K. G. J., and Simpson, M. J.: Plant- or
microbial-derived? A review on the molecular composition of stabilized soil
organic matter, Soil Biol. Biochem., 156, 108189,
https://doi.org/10.1016/j.soilbio.2021.108189, 2021. a
Bedoussac, L., Journet, E.-P., Hauggaard-Nielsen, H., Naudin, C., Corre-Hellou,
G., Jensen, E. S., Prieur, L., and Justes, E.: Ecological principles
underlying the increase of productivity achieved by cereal-grain legume
intercrops in organic farming. A review, Agron. Sustain.
Dev., 35, 911–935, https://doi.org/10.1007/s13593-014-0277-7, 2015. a
Bucka, F. B., Felde, V. J. M. N. L., Peth, S., and Kögel-Knabner, I.:
Disentangling the effects of OM quality and soil texture on microbially
mediated structure formation in artificial model soils, Geoderma, 403,
115213, https://doi.org/10.1016/j.geoderma.2021.115213, 2021. a
Cardinael, R., Guibert, H., Kouassi Brédoumy, S. T., Gigou, J., N'Goran,
K. E., and Corbeels, M.: Sustaining maize yields and soil carbon following
land clearing in the forest–savannah transition zone of West Africa:
Results from a 20-year experiment, Field Crop. Res., 275, 108335,
https://doi.org/10.1016/j.fcr.2021.108335, 2022. a, b
Castellano, M. J., Mueller, K. E., Olk, D. C., Sawyer, J. E., and Six, J.:
Integrating plant litter quality, soil organic matter stabilization, and the
carbon saturation concept, Glob. Change Biol., 21, 3200–3209,
https://doi.org/10.1111/gcb.12982, 2015. a
Chivenge, P., Vanlauwe, B., Gentile, R., Wangechi, H., Mugendi, D., Kessel,
C. v., and Six, J.: Organic and Mineral Input Management to Enhance
Crop Productivity in Central Kenya, Agron. J., 101,
1266–1275, https://doi.org/10.2134/agronj2008.0188x, 2009. a
Conant, R. T., Ryan, M. G., Ågren, G. I., Birge, H. E., Davidson, E. A.,
Eliasson, P. E., Evans, S. E., Frey, S. D., Giardina, C. P., Hopkins, F. M.,
Hyvönen, R., Kirschbaum, M. U. F., Lavallee, J. M., Leifeld, J., Parton,
W. J., Megan Steinweg, J., Wallenstein, M. D., Martin Wetterstedt, J. A., and
Bradford, M. A.: Temperature and soil organic matter decomposition rates –
synthesis of current knowledge and a way forward, Glob. Change Biol., 17,
3392–3404, https://doi.org/10.1111/j.1365-2486.2011.02496.x, 2011. a
Corbeels, M., Cardinael, R., Naudin, K., Guibert, H., and Torquebiau, E.: The 4
per 1000 goal and soil carbon storage under agroforestry and conservation
agriculture systems in sub-Saharan Africa, Soil Till. Res.,
188, 16–26, https://doi.org/10.1016/j.still.2018.02.015, 2019. a
Cotrufo, M. F., Wallenstein, M. D., Boot, C. M., Denef, K., and Paul, E.: The
Microbial Efficiency-Matrix Stabilization (MEMS) framework
integrates plant litter decomposition with soil organic matter stabilization:
do labile plant inputs form stable soil organic matter?, Glob. Change
Biol., 19, 988–995, https://doi.org/10.1111/gcb.12113, 2013. a, b, c
Cotrufo, M. F., Lavallee, J. M., Zhang, Y., Hansen, P. M., Paustian, K. H.,
Schipanski, M., and Wallenstein, M. D.: In-N-Out: A hierarchical
framework to understand and predict soil carbon storage and nitrogen
recycling, Glob. Change Biol., 27, 4465–4468, https://doi.org/10.1111/gcb.15782, 2021. a
Davidson, E. A. and Janssens, I. A.: Temperature sensitivity of soil carbon
decomposition and feedbacks to climate change, Nature, 440, 165–173,
https://doi.org/10.1038/nature04514, 2006. a
de Azevedo, E. B., Savian, J. V., do Amaral, G. A., de David, D. B., Gere,
J. I., Kohmann, M. M., Bremm, C., Jochims, F., Zubieta, A. S., Gonda, H. L.,
Bayer, C., and de Faccio Carvalho, P. C.: Feed intake, methane yield, and
efficiency of utilization of energy and nitrogen by sheep fed tropical
grasses, Trop. Anim. Health Pro., 53, 452,
https://doi.org/10.1007/s11250-021-02928-4, 2021. a
Denef, K. and Six, J.: Contributions of incorporated residue and living roots
to aggregate-associated and microbial carbon in two soils with different clay
mineralogy, Eur. J. Soil Sci., 57, 774–786,
https://doi.org/10.1111/j.1365-2389.2005.00762.x, 2006. a
Denef, K., Plante, A. F., and Six, J.: Characterization of soil organic matter,
in: Soil Carbon Dynamics: An Integrated Methodology, edited by:
Heinemeyer, A., Bahn, M., and Kutsch, W. L., 91–126, Cambridge
University Press, Cambridge, https://doi.org/10.1017/CBO9780511711794.007, 2009. a, b
Dickhoefer, U., Ramadhan, M. R., Apenburg, S., Buerkert, A., and Schlecht, E.:
Effects of mild water restriction on nutrient digestion and protein
metabolism in desert-adapted goats, Small Ruminant Res., 204, 106500,
https://doi.org/10.1016/j.smallrumres.2021.106500, 2021. a
Doetterl, S., Stevens, A., Six, J., Merckx, R., Van Oost, K., Casanova Pinto,
M., Casanova-Katny, A., Muñoz, C., Boudin, M., Zagal Venegas, E., and
Boeckx, P.: Soil carbon storage controlled by interactions between
geochemistry and climate, Nat. Geosci., 8, 780–783,
https://doi.org/10.1038/ngeo2516, 2015. a, b
FAO: World reference base for soil resources, no. 84 in World Soil
Resources Report, FAO, Rome, ISBN 92-5-104141-5, 1998. a
FAO: FAOSTAT Online Database, http://www.fao.org/ (last access: 5 August 2021), 2021. a
Frimmel, F. H. and Christman, R. F.: Humic substances and their role in the
environment, edited by: Frimmel, F. H., Bracewell, J. M., and Christman, R. F., John Wiley and Sons Ltd., ISBN 9780471918172, 1988. a
Fujisaki, K., Chevallier, T., Chapuis-Lardy, L., Albrecht, A., Razafimbelo, T.,
Masse, D., Ndour, Y. B., and Chotte, J.-L.: Soil carbon stock changes in
tropical croplands are mainly driven by carbon inputs: A synthesis,
Agr. Ecosyst. Environ., 259, 147–158,
https://doi.org/10.1016/j.agee.2017.12.008, 2018. a
Galicia, L. and García-Oliva, F.: Litter Quality of Two Remnant Tree
Species Affects Soil Microbial Activity in Tropical Seasonal
Pastures in Western Mexico, Arid Land Res. Manag., 25,
75–86, https://doi.org/10.1080/15324982.2010.528148, 2011. a
Gentile, R., Vanlauwe, B., van Kessel, C., and Six, J.: Managing N
availability and losses by combining fertilizer-N with different quality
residues in Kenya, Agr. Ecosyst. Environ., 131, 308–314,
https://doi.org/10.1016/j.agee.2009.02.003, 2009. a
Gentile, R., Vanlauwe, B., and Six, J.: Litter quality impacts short- but not
long-term soil carbon dynamics in soil aggregate fractions, Ecol.
Soc. Am., 21, 695–703, https://doi.org/10.1890/09-2325.1, 2011. a
Gram, G., Roobroeck, D., Pypers, P., Six, J., Merckx, R., and Vanlauwe, B.:
Combining organic and mineral fertilizers as a climate-smart integrated soil
fertility management practice in sub-Saharan Africa: A meta-analysis,
PLOS ONE, 15, e0239552, https://doi.org/10.1371/journal.pone.0239552, 2020. a
Guo, L. B. and Gifford, R. M.: Soil carbon stocks and land use change: A meta
analysis, Glob. Change Biol., 8, 345–360,
https://doi.org/10.1046/j.1354-1013.2002.00486.x, 2002. a
Hao, X., Han, X., Wang, S., and Li, L.-J.: Dynamics and composition of soil
organic carbon in response to 15 years of straw return in a Mollisol, Soil
Till. Res., 215, 105221, https://doi.org/10.1016/j.still.2021.105221, 2022. a
Hassink, J.: The capacity of soils to preserve organic C and N by their
association with clay and silt particles, Plant Soil, 191, 77–87,
https://doi.org/10.1023/A:1004213929699, 1997. a
IUSS Working Group: World reference base for soil resources 2014,
International soil classification system for naming soils and creating
legends for soil maps,
World Soil Resources Reports No. 106, FAO, Rome, https://doi.org/10.1017/S0014479706394902, 2014. a, b
Jackson, R. B., Lajtha, K., Crow, S. E., Hugelius, G., Kramer, M. G., and
Piñeiro, G.: The Ecology of Soil Carbon: Pools, Vulnerabilities,
and Biotic and Abiotic Controls, Annu. Rev. Ecol. Evol.
S., 48, 419–445, https://doi.org/10.1146/annurev-ecolsys-112414-054234,
2017. a
Kallenbach, C. M., Frey, S. D., and Grandy, A. S.: Direct evidence for
microbial-derived soil organic matter formation and its ecophysiological
controls, Nat. Commun., 7, 1–10, https://doi.org/10.1038/ncomms13630, 2016. a, b
Karhu, K., Gärdenäs, A. I., Heikkinen, J., Vanhala, P., Tuomi, M., and Liski,
J.: Impacts of organic amendments on carbon stocks of an agricultural soil
– Comparison of model-simulations to measurements, Geoderma, 189–190,
606–616, https://doi.org/10.1016/j.geoderma.2012.06.007, 2012. a
Kayani, I. B., Agumas, B., Musyoki, M., Nziguheba, G., Marohn, C., Benz, M.,
Vanlauwe, B., Cadisch, G., and Rasche, F.: Market access and resource
endowment define the soil fertility status of smallholder farming systems of
South-Kivu, DR Congo, Soil Use Manage., 37, 353–366,
https://doi.org/10.1111/sum.12691, 2021. a
Keller, A. B., Borer, E. T., Collins, S. L., DeLancey, L. C., Fay, P. A.,
Hofmockel, K. S., Leakey, A. D., Mayes, M. A., Seabloom, E. W., Walter,
C. A., Wang, Y., Zhao, Q., and Hobbie, S. E.: Soil carbon stocks in temperate
grasslands differ strongly across sites but are insensitive to decade-long
fertilization, Glob. Change Biol., 28, 1659–1677,
https://doi.org/10.1111/gcb.15988, 2022. a
Kihara, J., Bolo, P., Kinyua, M., Nyawira, S. S., and Sommer, R.: Soil health
and ecosystem services: Lessons from sub-Sahara Africa (SSA),
Geoderma, 370, 114342, https://doi.org/10.1016/j.geoderma.2020.114342, 2020. a
Kong, A. Y. Y., Six, J., Bryant, D. C., Denison, R. F., and van Kessel, C.: The
Relationship between Carbon Input, Aggregation, and Soil Organic
Carbon Stabilization in Sustainable Cropping Systems, Soil Sci.
Soc. Am. J., 69, 1078–1085, https://doi.org/10.2136/sssaj2004.0215,
2005. a
Kunlanit, B., Vityakon, P., Puttaso, A., Cadisch, G., and Rasche, F.:
Mechanisms controlling soil organic carbon composition pertaining to
microbial decomposition of biochemically contrasting organic residues:
Evidence from midDRIFTS peak area analysis, Soil Biol. Biochem.,
76, 100–108, https://doi.org/10.1016/j.soilbio.2014.05.006, 2014. a, b
Ladha, J. K., Reddy, C. K., Padre, A. T., and van Kessel, C.: Role of
Nitrogen Fertilization in Sustaining Organic Matter in Cultivated
Soils, J. Environ. Qual., 40, 1756–1766,
https://doi.org/10.2134/jeq2011.0064, 2011. a
Lal, R.: Digging deeper: A holistic perspective of factors affecting soil
organic carbon sequestration in agroecosystems, Glob. Change Biol., 24,
3285–3301, https://doi.org/10.1111/gcb.14054, 2018. a
Laub, M., Schlichenmeier, S., Vityakon, P., and Cadisch, G.: Litter Quality
and Microbes Explain Aggregation Differences in a Tropical Sandy
Soil, J. Soil Sci. Plant Nut., 22, 848–860,
https://doi.org/10.1007/s42729-021-00696-6, 2022. a, b
Laub, M., Corbeels, M., Mathu Ndungu, S., Mucheru-Muna, M. W., Mugendi, D.,
Necpalova, M., Van de Broek, M., Waswa, W., Vanlauwe, B., and Six, J.:
Combining manure with mineral N fertilizer maintains maize yields:
Evidence from four long-term experiments in Kenya, Field Crop. Res.,
291, 108788, https://doi.org/10.1016/j.fcr.2022.108788, 2023. a, b, c
Lavallee, J. M., Conant, R. T., Paul, E. A., and Cotrufo, M. F.: Incorporation
of shoot versus root-derived 13C and 15N into mineral-associated organic
matter fractions: results of a soil slurry incubation with dual-labelled
plant material, Biogeochemistry, 137, 379–393,
https://doi.org/10.1007/s10533-018-0428-z, 2018. a
Lee, J., Hopmans, J. W., Rolston, D. E., Baer, S. G., and Six, J.: Determining
soil carbon stock changes: Simple bulk density corrections fail,
Agr. Ecosyst. Environ., 134, 251–256,
https://doi.org/10.1016/j.agee.2009.07.006, 2009. a
Lenth, R. V.: emmeans: Estimated Marginal Means, aka Least-Squares Means, r package version 1.5.4,
https://github.com/rvlenth/emmeans (last access: 1 June 2023),
2021. a
Li, J., Sang, C., Yang, J., Qu, L., Xia, Z., Sun, H., Jiang, P., Wang, X., He,
H., and Wang, C.: Stoichiometric imbalance and microbial community regulate
microbial elements use efficiencies under nitrogen addition, Soil Biol.
Biochem., 156, 108207, https://doi.org/10.1016/j.soilbio.2021.108207,
2021. a
Li, M., Meador, T., Sauheitl, L., Guggenberger, G., and Angst, G.: Substrate
quality effects on stabilized soil carbon reverse with depth, Geoderma, 406,
115511, https://doi.org/10.1016/j.geoderma.2021.115511, 2022. a
Li, X.-F., Wang, Z.-G., Bao, X.-G., Sun, J.-H., Yang, S.-C., Wang, P., Wang,
C.-B., Wu, J.-P., Liu, X.-R., Tian, X.-L., Wang, Y., Li, J.-P., Wang, Y.,
Xia, H.-Y., Mei, P.-P., Wang, X.-F., Zhao, J.-H., Yu, R.-P., Zhang, W.-P.,
Che, Z.-X., Gui, L.-G., Callaway, R. M., Tilman, D., and Li, L.: Long-term
increased grain yield and soil fertility from intercropping, Nat.
Sustain., 4, 943–950, https://doi.org/10.1038/s41893-021-00767-7, 2021b. a
Mainka, M., Summerauer, L., Wasner, D., Garland, G., Griepentrog, M., Berhe, A. A., and Doetterl, S.: Soil geochemistry as a driver of soil organic matter composition: insights from a soil chronosequence, Biogeosciences, 19, 1675–1689, https://doi.org/10.5194/bg-19-1675-2022, 2022. a
Malik, A. A., Puissant, J., Buckeridge, K. M., Goodall, T., Jehmlich, N.,
Chowdhury, S., Gweon, H. S., Peyton, J. M., Mason, K. E., van Agtmaal, M.,
Blaud, A., Clark, I. M., Whitaker, J., Pywell, R. F., Ostle, N., Gleixner,
G., and Griffiths, R. I.: Land use driven change in soil pH affects
microbial carbon cycling processes, Nat. Commun., 9, 3591,
https://doi.org/10.1038/s41467-018-05980-1, 2018. a
Malézieux, E., Crozat, Y., Dupraz, C., Laurans, M., Makowski, D.,
Ozier-Lafontaine, H., Rapidel, B., de Tourdonnet, S., and Valantin-Morison,
M.: Mixing plant species in cropping systems: concepts, tools and models. A
review, Agron. Sustain. Dev., 29, 43–62,
https://doi.org/10.1051/agro:2007057, 2009. a
Manzoni, S., Taylor, P., Richter, A., Porporato, A., and Ågren, G. I.:
Environmental and stoichiometric controls on microbial carbon-use efficiency
in soils, New Phytol., 196, 79–91,
https://doi.org/10.1111/j.1469-8137.2012.04225.x, 2012. a
Manzoni, S., Čapek, P., Porada, P., Thurner, M., Winterdahl, M., Beer, C., Brüchert, V., Frouz, J., Herrmann, A. M., Lindahl, B. D., Lyon, S. W., Šantrůčková, H., Vico, G., and Way, D.: Reviews and syntheses: Carbon use efficiency from organisms to ecosystems – definitions, theories, and empirical evidence, Biogeosciences, 15, 5929–5949, https://doi.org/10.5194/bg-15-5929-2018, 2018. a, b
Mtangadura, T. J., Mtambanengwe, F., Nezomba, H., Rurinda, J., and Mapfumo, P.:
Why organic resources and current fertilizer formulations in Southern
Africa cannot sustain maize productivity: Evidence from a long-term
experiment in Zimbabwe, PLOS ONE, 12, e0182840,
https://doi.org/10.1371/journal.pone.0182840,
2017. a, b, c
Palm, C. A., Gachengo, C. N., Delve, R. J., Cadisch, G., and Giller, K. E.:
Organic inputs for soil fertility management in tropical agroecosystems:
application of an organic resource database, Agr. Ecosyst.
Environ., 83, 27–42, https://doi.org/10.1016/S0167-8809(00)00267-X,
2001a. a, b, c
Palm, C. A., Giller, K. E., Mafongoya, P. L., and Swift, M. J.: Management of
organic matter in the tropics: Translating theory into practice, Nutr.
Cycl. Agroecosys., 61, 63–75, https://doi.org/10.1023/A:1013318210809,
2001b. a, b
Piepho, H.-P.: An Algorithm for a Letter-Based Representation of
All-Pairwise Comparisons, J. Comput. Graph.
Stat., 13, 456–466, https://doi.org/10.1198/1061860043515, 2004. a
Pingthaisong, W. and Vityakon, P.: Nonadditive Effects on Decomposition of
a Mixture of Rice Straw and Groundnut Stover Applied to a Sandy
Soil, Agronomy, 11, 1030, https://doi.org/10.3390/agronomy11061030, 2021. a
Pinheiro, J., Bates, D., and R-core: nlme: Linear and Nonlinear Mixed Effects
Models, r
package version 3.1-152, https://svn.r-project.org/R-packages/trunk/nlme/ (last access: 1 June 2023), 2021. a
Prescott, C. E., Rui, Y., Cotrufo, M. F., and Grayston, S. J.: Managing plant
surplus carbon to generate soil organic matter in regenerative agriculture,
J. Soil Water Conserv., 76, 99A–104A,
https://doi.org/10.2489/jswc.2021.0920A, 2021. a, b
Pretty, J. and Bharucha, Z. P.: Sustainable intensification in agricultural
systems, Ann. Bot., 114, 1571–1596, https://doi.org/10.1093/aob/mcu205, 2014. a
Puttaso, A., Vityakon, P., Rasche, F., Saenjan, P., Treloges, V., and Cadisch,
G.: Does Organic Residue Quality Influence Carbon Retention in a
Tropical Sandy Soil?, Soil Sci. Soc. Am. J., 77,
1001–1001, https://doi.org/10.2136/sssaj2012.0209, 2013. a, b, c
Rasse, D. P., Rumpel, C., and Dignac, M.-F.: Is soil carbon mostly root carbon?
Mechanisms for a specific stabilisation, Plant Soil, 269, 341–356,
https://doi.org/10.1007/s11104-004-0907-y, 2005. a
R Core Team: R: A Language and Environment for Statistical Computing, R
Foundation for Statistical Computing, Vienna, Austria,
https://www.R-project.org/ (last access: 1 June 2023), 2021. a
Reichenbach, M., Fiener, P., Garland, G., Griepentrog, M., Six, J., and Doetterl, S.: The role of geochemistry in organic carbon stabilization against microbial decomposition in tropical rainforest soils, SOIL, 7, 453–475, https://doi.org/10.5194/soil-7-453-2021, 2021. a
Rufino, M. C., Rowe, E. C., Delve, R. J., and Giller, K. E.: Nitrogen cycling
efficiencies through resource-poor African crop–livestock systems,
Agr. Ecosyst. Environ., 112, 261–282,
https://doi.org/10.1016/j.agee.2005.08.028, 2006. a
Running, S. W., Nemani, R. R., Heinsch, F. A., Zhao, M., Reeves, M., and
Hashimoto, H.: A Continuous Satellite-Derived Measure of Global
Terrestrial Primary Production, BioScience, 54, 547–560,
https://doi.org/10.1641/0006-3568(2004)054[0547:ACSMOG]2.0.CO;2, 2004. a
Rusinamhodzi, L., Corbeels, M., Zingore, S., Nyamangara, J., and Giller, K. E.:
Pushing the envelope? Maize production intensification and the role of
cattle manure in recovery of degraded soils in smallholder farming areas of
Zimbabwe, Field Crop. Res., 147, 40–53,
https://doi.org/10.1016/j.fcr.2013.03.014, 2013. a
Ryan, M. G. and Law, B. E.: Interpreting, measuring, and modeling soil
respiration, Biogeochemistry, 73, 3–27, https://doi.org/10.1007/s10533-004-5167-7,
2005. a
Sanderman, J., Hengl, T., and Fiske, G. J.: Soil carbon debt of 12,000 years of
human land use, P. Natl. Acad. Sci. USA, 114,
9575–9580, https://doi.org/10.1073/pnas.1706103114, 2017. a
Schweizer, S. A., Mueller, C. W., Höschen, C., Ivanov, P., and Kögel-Knabner,
I.: The role of clay content and mineral surface area for soil organic carbon
storage in an arable toposequence, Biogeochemistry, 156, 401–420,
https://doi.org/10.1007/s10533-021-00850-3, 2021. a
Sileshi, G. W., Nhamo, N., Mafongoya, P. L., and Tanimu, J.: Stoichiometry of
animal manure and implications for nutrient cycling and agriculture in
sub-Saharan Africa, Nutr. Cycl. Agroecosys., 107, 91–105,
https://doi.org/10.1007/s10705-016-9817-7, 2017. a
Sileshi, G. W., Jama, B., Vanlauwe, B., Negassa, W., Harawa, R., Kiwia, A., and
Kimani, D.: Nutrient use efficiency and crop yield response to the combined
application of cattle manure and inorganic fertilizer in sub-Saharan
Africa, Nutr. Cycl. Agroecosys., 113, 181–199,
https://doi.org/10.1007/s10705-019-09974-3, 2019. a, b
Silva, V. B. d., Silva, A. P. d., Dias, B. d. O., Araujo, J. L., Santos, D.,
and Franco, R. P.: Decomposição e liberação de N, P e K de esterco
bovino e de cama de frango isolados ou misturados, Rev. Bras.
Ciênc. Solo, 38, 1537–1546, https://doi.org/10.1590/S0100-06832014000500019,
2014. a
Silva-Sánchez, A., Soares, M., and Rousk, J.: Testing the dependence of
microbial growth and carbon use efficiency on nitrogen availability, pH,
and organic matter quality, Soil Biol. Biochem., 134, 25–35,
https://doi.org/10.1016/j.soilbio.2019.03.008, 2019. a
Sinsabaugh, R. L., Manzoni, S., Moorhead, D. L., and Richter, A.: Carbon use
efficiency of microbial communities: stoichiometry, methodology and
modelling, Ecol. Lett., 16, 930–939, https://doi.org/10.1111/ele.12113, 2013. a, b
Six, J., Feller, C., Denef, K., Ogle, S. M., Sa, J. C. d. M., and Albrecht, A.:
Soil organic matter, biota and aggregation in temperate and tropical soils –
Effects of no-tillage, Agronomie, 22, 755–775, https://doi.org/10.1051/agro:2002043, 2002. a, b
Sokol, N. W. and Bradford, M. A.: Microbial formation of stable soil carbon is
more efficient from belowground than aboveground input, Nat. Geosci.,
12, 46–53, https://doi.org/10.1038/s41561-018-0258-6, 2019. a
Sokol, N. W., Sanderman, J., and Bradford, M. A.: Pathways of
mineral-associated soil organic matter formation: Integrating the role of
plant carbon source, chemistry, and point of entry, Glob. Change Biol.,
25, 12–24, https://doi.org/10.1111/gcb.14482, 2019. a
Solomon, D., Lehmann, J., Kinyangi, J., Amelung, W., Lobe, I., Pell, A., Riha,
S., Ngoze, S., Verchot, L., Mbugua, D., Skjemstad, J., and Schäfer, T.:
Long-term impacts of anthropogenic perturbations on dynamics and speciation
of organic carbon in tropical forest and subtropical grassland ecosystems,
Glob. Change Biol., 13, 511–530, https://doi.org/10.1111/j.1365-2486.2006.01304.x,
2007. a
Sommer, R., Paul, B. K., Mukalama, J., and Kihara, J.: Reducing losses but
failing to sequester carbon in soils – the case of Conservation
Agriculture and Integrated Soil Fertility Management in the humid
tropical agro-ecosystem of Western Kenya, Agr. Ecosyst.
Environ., 254, 82–91, https://doi.org/10.1016/j.agee.2017.11.004, 2018. a, b, c
Srinivasarao, C., Venkateswarlu, B., Lal, R., Singh, A. K., Kundu, S., Vittal,
K. P. R., Ramachandrappa, B. K., and Gajanan, G. N.: Long-term effects of
crop residues and fertility management on carbon sequestration and agronomic
productivity of groundnut–finger millet rotation on an Alfisol in
southern India, Int. J. Agr. Sustain., 10,
230–244, https://doi.org/10.1080/14735903.2012.662392, 2012. a
Tessema, B., Sommer, R., Piikki, K., Söderström, M., Namirembe, S.,
Notenbaert, A., Tamene, L., Nyawira, S., and Paul, B.: Potential for soil
organic carbon sequestration in grasslands in East African countries: A
review, Grassl. Sci., 66, 135–144, https://doi.org/10.1111/grs.12267, 2020. a
Tittonell, P., Muriuki, A., Klapwijk, C. J., Shepherd, K. D., Coe, R., and
Vanlauwe, B.: Soil Heterogeneity and Soil Fertility Gradients in
Smallholder Farms of the East African Highlands, Soil Sci.
Soc. Am. J., 77, 525–538, https://doi.org/10.2136/sssaj2012.0250,
2013. a
Todd-Brown, K. E. O., Randerson, J. T., Post, W. M., Hoffman, F. M., Tarnocai, C., Schuur, E. A. G., and Allison, S. D.: Causes of variation in soil carbon simulations from CMIP5 Earth system models and comparison with observations, Biogeosciences, 10, 1717–1736, https://doi.org/10.5194/bg-10-1717-2013, 2013. a
Van de Broek, M., Ghiasi, S., Decock, C., Hund, A., Abiven, S., Friedli, C., Werner, R. A., and Six, J.: The soil organic carbon stabilization potential of old and new wheat cultivars: a 13CO2-labeling study, Biogeosciences, 17, 2971–2986, https://doi.org/10.5194/bg-17-2971-2020, 2020. a
Vanlauwe, B. and Giller, K. E.: Popular myths around soil fertility management
in sub-Saharan Africa, Agr. Ecosyst. Environ., 116,
34–46, https://doi.org/10.1016/j.agee.2006.03.016, 2006. a, b
Vanlauwe, B., Bationo, A., Chianu, J., Giller, K., Merckx, R., Mokwunye, U.,
Ohiokpehai, O., Pypers, P., Tabo, R., Shepherd, K., Smaling, E., Woomer, P.,
and Sanginga, N.: Integrated Soil Fertility Management: Operational
Definition and Consequences for Implementation and Dissemination,
Outlook Agr., 39, 17–24, https://doi.org/10.5367/000000010791169998, 2010. a
Vanlauwe, B., Descheemaeker, K., Giller, K. E., Huising, J., Merckx, R., Nziguheba, G., Wendt, J., and Zingore, S.: Integrated soil fertility management in sub-Saharan Africa: unravelling local adaptation, SOIL, 1, 491–508, https://doi.org/10.5194/soil-1-491-2015, 2015. a, b, c, d
Vanlauwe, B., Six, J., Laub, M., Mathu, S., and Mugendi, D.: ISFM/SOM long-term trials soil data, IITA [data set], https://doi.org/10.25502/wdh5-6c13/d, 2022. a, b
Veloso, M. G., Angers, D. A., Tiecher, T., Giacomini, S., Dieckow, J., and
Bayer, C.: High carbon storage in a previously degraded subtropical soil
under no-tillage with legume cover crops, Agr. Ecosyst.
Environ., 268, 15–23, https://doi.org/10.1016/j.agee.2018.08.024, 2018. a
Wawire, A. W., Csorba, Á., Tóth, J. A., Michéli, E., Szalai, M., Mutuma, E.,
and Kovács, E.: Soil fertility management among smallholder farmers in
Mount Kenya East region, Heliyon, 7, e06488,
https://doi.org/10.1016/j.heliyon.2021.e06488, 2021. a
Wei, X., Shao, M., Gale, W., and Li, L.: Global pattern of soil carbon losses
due to the conversion of forests to agricultural land, Sci. Rep.-UK, 4,
4062, https://doi.org/10.1038/srep04062, 2014. a
Wendt, J. W. and Hauser, S.: An equivalent soil mass procedure for monitoring
soil organic carbon in multiple soil layers, Eur. J. Soil
Sci., 64, 58–65, https://doi.org/10.1111/ejss.12002, 2013. a
Wiesmeier, M., Mayer, S., Burmeister, J., Hübner, R., and Kögel-Knabner, I.:
Feasibility of the 4 per 1000 initiative in Bavaria: A reality check of
agricultural soil management and carbon sequestration scenarios, Geoderma,
369, 114333, https://doi.org/10.1016/j.geoderma.2020.114333, 2020. a
Woomer, P. and Swift, M. J. (Eds.): The Biological Management of Tropical Soil
Fertility, John Wiley, Chichester, UK, ISBN 978-0-471-95095-0, 1994. a
Xiao, Q., Huang, Y., Wu, L., Tian, Y., Wang, Q., Wang, B., Xu, M., and Zhang,
W.: Long-term manuring increases microbial carbon use efficiency and
mitigates priming effect via alleviated soil acidification and resource
limitation, Biol. Fert. Soils, 57, 925–934, https://doi.org/10.1007/s00374-021-01583-z,
2021. a
Zech, W., Senesi, N., Guggenberger, G., Kaiser, K., Lehmann, J., Miano, T. M.,
Miltner, A., and Schroth, G.: Factors controlling humification and
mineralization of soil organic matter in the tropics, Geoderma, 79, 117–161,
https://doi.org/10.1016/S0016-7061(97)00040-2, 1997. a
Zha, Y., Wu, X.-P., Gong, F.-F., Xu, M.-G., Zhang, H.-M., Chen, L.-M., Huang,
S.-M., and Cai, D.-X.: Long-term organic and inorganic fertilizations
enhanced basic soil productivity in a fluvo-aquic soil, J.
Integr. Agr., 14, 2477–2489, https://doi.org/10.1016/S2095-3119(15)61191-1,
2015.
a
Zuur, A., Ieno, E. N., Walker, N., Saveliev, A. A., and Smith, G. M.: Mixed
Effects Models and Extensions in Ecology with R, Statistics for
Biology and Health, edited by: Gail, M., Krickeberg, K., Samet, J. M.,
Tsiatis, A., and Wong, W., Springer-Verlag, New York,
https://doi.org/10.1007/978-0-387-87458-6, 2009. a
Short summary
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.
In sub-Saharan Africa, long-term low-input maize cropping threatens soil fertility. We studied...