Articles | Volume 7, issue 2
https://doi.org/10.5194/soil-7-717-2021
© Author(s) 2021. 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-7-717-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Original research article
| 
27 Oct 2021
Original research article |
| 27 Oct 2021
| 27 Oct 2021
Estimation of soil properties with mid-infrared soil spectroscopy across yam production landscapes in West Africa
Philipp Baumann
CORRESPONDING AUTHOR
Group of Sustainable Agroecosystems, Institute of Agricultural Sciences, ETH Zurich, 8092 Zürich, Switzerland
Juhwan Lee
Department of Smart Agro-industry, Gyeongsang National University, Jinju, 52725, Republic of Korea
Emmanuel Frossard
Group of Plant Nutrition, Institute of Agricultural Sciences, ETH Zurich, 8315 Lindau, Switzerland
Laurie Paule Schönholzer
Group of Plant Nutrition, Institute of Agricultural Sciences, ETH Zurich, 8315 Lindau, Switzerland
Lucien Diby
World Agroforestry Centre (ICRAF), Côte d’Ivoire Country Programme, BP 2823 Abidjan, Côte d’Ivoire
Valérie Kouamé Hgaza
Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, 01 BP 1303 Abidjan, Côte d’Ivoire
Département d’Agrophysiologie des Plantes, Université Peleforo Gon Coulibaly, BP 1328 Korhogo, Côte d’Ivoire
Delwende Innocent Kiba
Group of Plant Nutrition, Institute of Agricultural Sciences, ETH Zurich, 8315 Lindau, Switzerland
Département Gestion des Ressources Naturelles et Systèmes de Production, Centre National de la Recherche Scientifique et Technologique, Institut de l'Environnement et Recherches Agricoles, 01 BP 476 Ouagadougou, Burkina Faso
Andrew Sila
Land Health Decisions, World Agroforestry Centre (ICRAF), Nairobi, Kenya
Keith Sheperd
Land Health Decisions, World Agroforestry Centre (ICRAF), Nairobi, Kenya
Johan Six
Group of Sustainable Agroecosystems, Institute of Agricultural Sciences, ETH Zurich, 8092 Zürich, Switzerland
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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.
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
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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.
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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.
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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.
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
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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
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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.
Frank Hagedorn, Josephine Imboden, Pavel A. Moiseev, Decai Gao, Emmanuel Frossard, Patrick Schleppi, Daniel Christen, Konstantin Gavazov, and Jasmin Fetzer
Biogeosciences, 22, 2959–2977, https://doi.org/10.5194/bg-22-2959-2025, https://doi.org/10.5194/bg-22-2959-2025, 2025
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At treeline, plant species change abruptly from low-stature plants in tundra to trees in forests. Our study documents that from tundra towards forest, the litter layer becomes strongly enriched in nutrients. We show that these litter quality changes alter nutrient processing by soil microbes and increase nutrient release during decomposition in forests compared to tundra. The associated improvement in nutrient availability in forests potentially stimulates tree growth and treeline shifts.
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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Marijn Van de Broek, Fiona Stewart-Smith, Moritz Laub, Marc Corbeels, Monicah Wanjiku Mucheru-Muna, Daniel Mugendi, Wycliffe Waswa, Bernard Vanlauwe, and Johan Six
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Roxanne Daelman, Marijn Bauters, Matti Barthel, Emmanuel Bulonza, Lodewijk Lefevre, José Mbifo, Johan Six, Klaus Butterbach-Bahl, Benjamin Wolf, Ralf Kiese, and Pascal Boeckx
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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.
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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
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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
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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
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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.
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
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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.
Jasmin Fetzer, Emmanuel Frossard, Klaus Kaiser, and Frank Hagedorn
Biogeosciences, 19, 1527–1546, https://doi.org/10.5194/bg-19-1527-2022, https://doi.org/10.5194/bg-19-1527-2022, 2022
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As leaching is a major pathway of nitrogen and phosphorus loss in forest soils, we investigated several potential drivers in two contrasting beech forests. The composition of leachates, obtained by zero-tension lysimeters, varied by season, and climatic extremes influenced the magnitude of leaching. Effects of nitrogen and phosphorus fertilization varied with soil nutrient status and sorption properties, and leaching from the low-nutrient soil was more sensitive to environmental factors.
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.
Juhwan Lee, Raphael A. Viscarra Rossel, Mingxi Zhang, Zhongkui Luo, and Ying-Ping Wang
Biogeosciences, 18, 5185–5202, https://doi.org/10.5194/bg-18-5185-2021, https://doi.org/10.5194/bg-18-5185-2021, 2021
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We performed Roth C simulations across Australia and assessed the response of soil carbon to changing inputs and future climate change using a consistent modelling framework. Site-specific initialisation of the C pools with measurements of the C fractions is essential for accurate simulations of soil organic C stocks and composition at a large scale. With further warming, Australian soils will become more vulnerable to C loss: natural environments > native grazing > cropping > modified grazing.
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
Short summary
Short summary
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
Short summary
Short summary
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.
Jolanda E. Reusser, René Verel, Daniel Zindel, Emmanuel Frossard, and Timothy I. McLaren
Biogeosciences, 17, 5079–5095, https://doi.org/10.5194/bg-17-5079-2020, https://doi.org/10.5194/bg-17-5079-2020, 2020
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Inositol phosphates (IPs) are a major pool of organic P in soil. However, information on their diversity and abundance in soil is limited. We isolated IPs from soil and characterised them using solution nuclear magnetic resonance (NMR) spectroscopy. For the first time, we provide direct spectroscopic evidence for the existence of a multitude of lower-order IPs in soil extracts previously not detected with NMR. Our findings will help provide new insight into the cycling of IPs in ecosystems.
Cited articles
Abbott, L. K. and Murphy, D. V. (Eds.): Soil Biological Fertility: A Key
to Sustainable Land Use in Agriculture, Springer Netherlands, available at:
https://www.springer.com/de/book/9781402017568 (last access: 1 October 2021), 2007. a
Abdi, D., Tremblay, G. F., Ziadi, N., Bélanger, G., and Parent, L.-É.:
Predicting Soil Phosphorus-Related Properties Using Near-Infrared
Reflectance Spectroscopy, Soil Sci. Soc. Am. J., 76,
2318–2326, https://doi.org/10.2136/sssaj2012.0155, 2012. a
Baumann, P.: philipp-baumann/simplerspec: Beta release simplerspec 0.1.0 for
zenodo, Zenodo [software], https://doi.org/10.5281/zenodo.3303637, 2019. a
Baumann, P.: Philipp-baumann/yamsys-soilspec-publication: Open data and code
(manuscript submission): Estimation of soil properties with mid-infrared
soil spectroscopy across yam production landscapes in West Africa, Zenodo [data set, code],
https://doi.org/10.5281/zenodo.4358606, 2020. a, b
Bouyoucos, G. J.: A recalibration of the hydrometer method for making
mechanical analysis of soils, Agron. J., 43, 434–438, 1951. a
Breiman, L., Friedman, J., Stone, C., and Olshen, R.: Classification and
Regression Trees, The Wadsworth and Brooks-Cole
statistics-probability series, Taylor & Francis, available at:
https://books.google.ch/books?id=JwQx-WOmSyQC (last access: 1 October 2021), 1984. a
Cambou, A., Cardinael, R., Kouakoua, E., Villeneuve, M., Durand, C., and
Barthès, B. G.: Prediction of soil organic carbon stock using visible and
near infrared reflectance spectroscopy (VNIRS) in the field, Geoderma, 261,
151–159, https://doi.org/10.1016/j.geoderma.2015.07.007, 2016. a
Chong, I.-G. and Jun, C.-H.: Performance of some variable selection methods
when multicollinearity is present, Chemometr. Intell. Lab., 78, 103–112, https://doi.org/10.1016/j.chemolab.2004.12.011, 2005. a
Clairotte, M., Grinand, C., Kouakoua, E., Thébault, A., Saby, N. P., Bernoux,
M., and Barthès, B. G.: National calibration of soil organic carbon
concentration using diffuse infrared reflectance spectroscopy, Geoderma, 276,
41–52, https://doi.org/10.1016/j.geoderma.2016.04.021, 2016. a
Cornet, D., Sierra, J., Tournebize, R., Gabrielle, B., and Lewis, F. I.:
Bayesian Network Modeling of Early Growth Stages Explains Yam Interplant
Yield Variability and Allows for Agronomic Improvements in West Africa,
Eur. J. Agron., 75, 80–88, https://doi.org/10.1016/j.eja.2016.01.009,
2016. a
Cécillon, L., Barthès, B. G., Gomez, C., Ertlen, D., Genot, V., Hedde, M.,
Stevens, A., and Brun, J. J.: Assessment and monitoring of soil quality using
near-infrared reflectance spectroscopy (NIRS), Eur. J. Soil
Sci., 60, 770–784, https://doi.org/10.1111/j.1365-2389.2009.01178.x, 2009. a
Diby, L. N., Hgaza, V. K., Tie, T. B., ASSA, A., Carsky, R., Girardin, O., and
Frossard, E.: Productivity of Yams (Dioscorea Spp.) as Affected by Soil
Fertility, J. Anim. Plant Sci., 5, 494–506, 2009. a
Diby, L. N., Tie, B. T., Girardin, O., Sangakkara, R., and Frossard, E.: Growth
and Nutrient Use Efficiencies of Yams (Dioscorea Spp.) Grown
in Two Contrasting Soils of West Africa, Int. J.
Agron., 2011, 1–8, https://doi.org/10.1155/2011/175958, 2011. a
Enesi, R. O., Hauser, S., Lopez-Montez, A., and Osonubi, O.: Yam Tuber and
Maize Grain Yield Response to Cropping System Intensification in South-West
Nigeria, Arch. Agron. Soil Sci., 64, 953–966,
https://doi.org/10.1080/03650340.2017.1404580, 2018. a
Enyi, B. A. C.: Effect of Staking, Nitrogen and Potassium on Growth and
Development in Lesser Yams: Dioscorea Esculenta, Ann. Appl.
Biol., 72, 211–219, https://doi.org/10.1111/j.1744-7348.1972.tb01287.x, 1972. a
Food and Agriculture Organization of the United Nations: FAOSTAT statistics
database, available at: http://www.fao.org/3/i3794en/I3794en.pdf (last access: 1 October 2021), 2019. a
Foster, H. L.: The Basic Factors Which Determine Inherent Soil Fertility in
Uganda, J. Soil Sci., 32, 149–160,
https://doi.org/10.1111/j.1365-2389.1981.tb01693.x, 1981. a
Frossard, E., Aighewi, B. A., Aké, S., Barjolle, D., Baumann, P., Bernet, T.,
Dao, D., Diby, L. N., Floquet, A., Hgaza, V. K., Ilboudo, L. J., Kiba, D. I.,
Mongbo, R. L., Nacro, H. B., Nicolay, G. L., Oka, E., Ouattara, Y. F., Pouya,
N., Senanayake, R. L., Six, J., and Traoré, O. I.: The Challenge of
Improving Soil Fertility in Yam Cropping Systems of West
Africa, Front. Plant Sci., 1953, 1–8, https://doi.org/10.3389/fpls.2017.01953, 2017. a, b, c, d
Guerrero, C., Wetterlind, J., Stenberg, B., Mouazen, A. M., Gabarrón-Galeote,
M. A., Ruiz-Sinoga, J. D., Zornoza, R., and Viscarra Rossel, R. A.: Do We
Really Need Large Spectral Libraries for Local Scale SOC Assessment with
NIR Spectroscopy?, Soil Till. Res., 155, 501–509,
https://doi.org/10.1016/j.still.2015.07.008, 2016. a
Hendershot, W. H. and Duquette, M.: A simple barium chloride method for
determining cation exchange capacity and exchangeable cations, Soil Sci.
Soc. Am. J., 50, 605–608, 1986. a
Hgaza, V. K., Diby, L. N., Tié, T. B., Tschannen, A., Aké, S., Assa,
A., and Frossard, E.: Growth and Distribution of Roots of Dioscorea Alata
L. Do Not Respond to Mineral Fertilizer Application, Open Plant Sci.
J., 5, 14–22, 2011. a
Hillier, S., Brydson, R., Delbos, E., Fraser, T., Gray, N., Pendlowski, H.,
Phillips, I., Robertson, J., and Wilson, I.: Correlations among the
mineralogical and physical properties of halloysite nanotubes (HNTs), Clay
Miner., 51, 325–350, https://doi.org/10.1180/claymin.2016.051.3.11, 2016. a
Janik, L. J., Skjemstad, J. O., and Merry, R. H.: Can mid infrared diffuse
reflectance analysis replace soil extractions?, Aust. J.
Exp. Agr., 38, 681, https://doi.org/10.1071/EA97144, 1998. a, b
Johnson, J.-M., Vandamme, E., Senthilkumar, K., Sila, A., Shepherd, K. D., and
Saito, K.: Near-infrared, mid-infrared or combined diffuse reflectance
spectroscopy for assessing soil fertility in rice fields in sub-Saharan
Africa, Geoderma, 354, 113840, https://doi.org/10.1016/j.geoderma.2019.06.043,
2019. a
Kang, B. T. and Wilson, J. E.: Effect of mound size and fertilizer on white
Guinea yam (Dioscorea rotundata) in Southern Nigeria, Plant Soil,
61, 319–327, https://doi.org/10.1007/BF02182013, 1981. a
Kassi, S.-P. A., Koné, A. W., Tondoh, J. E., and Koffi, B. Y.: Chromoleana
Odorata Fallow-Cropping Cycles Maintain Soil Carbon Stocks and Yam Yields 40
Years after Conversion of Native- to Farmland, Implications for Forest
Conservation, Agr. Ecosyst. Environ., 247, 298–307,
https://doi.org/10.1016/j.agee.2017.06.044, 2017. a
Kiba, D. I., Hgaza, V. K., Aighewi, B., Aké, S., Barjolle, D., Bernet, T.,
Diby, L. N., Ilboudo, L. J., Nicolay, G., Oka, E., Ouattara, F. Y., Pouya,
N., Six, J., and Frossard, E.: A Transdisciplinary Approach for the
Development of Sustainable Yam (Dioscorea Sp.) Production in
West Africa, Sustainability, 12, 4016, https://doi.org/10.3390/su12104016, 2020. a
Kim, J.-H.: Estimating classification error rate: Repeated cross-validation,
repeated hold-out and bootstrap, Comput. Stat. Data Anal.,
53, 3735–3745, https://doi.org/10.1016/j.csda.2009.04.009, 2009. a
Kuhn, M., Wing, J., Weston, S., A., W., Keefer, C., Engelhardt, A., Cooper, T.,
Mayer, Z., Kenkel, B., Benesty, M., Lescarbeau, R., Ziem, A., Scrucca, L.,
Tang, Y., Candan, C., and Hunt, T.: caret: Classification and Regression
Training, available at: https://CRAN.R-project.org/package=caret (last access: 1 October 2021), R package
version 6.0-82, 2019. a
Lindsay, W. L. and Norvell, W. A.: Development of a DTPA soil test for zinc,
iron, manganese, and copper, Soil science society of America journal, 42,
421–428, 1978. a
Lyon, R. J. P. and Tuddenham, W. M.: Infra-Red Determination of the
Kaolin Group Minerals, Nature, 185, 835–836, https://doi.org/10.1038/185835a0, 1960. a
Madejová, J., Kečkés, J., Pálková, H., and Komadel, P.: Identification of
components in smectite/kaolinite mixtures, Clay Miner., 37, 377–388,
https://doi.org/10.1180/0009855023720042, 2002. a, b
Martens, H. and Naes, T.: Multivariate Calibration, Wiley Chichester, 1989. a
Mevik, B.-H., Wehrens, R., and Liland, K. H.: pls: Partial Least Squares and
Principal Component Regression, available at:
https://CRAN.R-project.org/package=pls (last access: 1 October 2021), R package version
2.7-1, 2019. a
Molinaro, A. M., Simon, R., and Pfeiffer, R. M.: Prediction error estimation: a
comparison of resampling methods, Bioinformatics, 21, 3301–3307,
https://doi.org/10.1093/bioinformatics/bti499, 2005. a
Nocita, M., Stevens, A., van Wesemael, B., Aitkenhead, M., Bachmann, M.,
Barthès, B., Ben Dor, E., Brown, D. J., Clairotte, M., Csorba, A., Dardenne,
P., Demattê, J. A., Genot, V., Guerrero, C., Knadel, M., Montanarella, L.,
Noon, C., Ramirez-Lopez, L., Robertson, J., Sakai, H., Soriano-Disla, J. M.,
Shepherd, K. D., Stenberg, B., Towett, E. K., Vargas, R., and Wetterlind, J.:
Soil Spectroscopy: An Alternative to Wet Chemistry for Soil
Monitoring, in: Advances in Agronomy, Vol. 132, Elsevier, 139–159,
https://doi.org/10.1016/bs.agron.2015.02.002, 2015. a, b, c, d
O'Sullivan, J. N. and Jenner, R.: Nutrient Deficiencies in Greater Yam
and Their Effects on Leaf Nutrient Concentrations, J. Plant
Nutr., 29, 1663–1674, https://doi.org/10.1080/01904160600851569, 2006. a, b, c, d
Padwick, G. W.: Fifty Years of Experimental Agriculture
II. The Maintenance of Soil Fertility in Tropical Africa: A
Review, Exp. Agr., 19, 293–310,
https://doi.org/10.1017/S001447970001276X, 1983. a
Parfitt, R. L., Atkinson, R. J., and Smart, R. S. C.: The Mechanism of
Phosphate Fixation by Iron Oxides, Soil Sci. Soc. Am.
J., 39, 837–841, https://doi.org/10.2136/sssaj1975.03615995003900050017x, 1975. a
R Core Team: R: A Language and Environment for Statistical Computing, R
Foundation for Statistical Computing, Vienna, Austria, available at:
https://www.R-project.org/ (last access: 1 October 2021), 2017. a
Rossel, R. A. V. and Webster, R.: Predicting soil properties from the
Australian soil visible–near infrared spectroscopic database, Europ.
J. Soil Sci., 63, 848–860,
https://doi.org/10.1111/j.1365-2389.2012.01495.x, 2012. a
Rossel, R. V. and Behrens, T.: Using data mining to model and interpret soil
diffuse reflectance spectra, Geoderma, 158, 46–54,
https://doi.org/10.1016/j.geoderma.2009.12.025, 2010. a
Sanderman, J., Savage, K., and Dangal, S. R. S.: Mid-Infrared Spectroscopy for
Prediction of Soil Health Indicators in the United States, Soil Sci.
Soc. Am. J., 84, 251–261, https://doi.org/10.1002/saj2.20009, 2020. a
Savitzky, A. and Golay, M. J. E.: Smoothing and Differentiation of Data by
Simplified Least Squares Procedures., Anal. Chem., 36, 1627–1639,
https://doi.org/10.1021/ac60214a047, 1964. a
Sila, A. M., Shepherd, K. D., and Pokhariyal, G. P.: Evaluating the utility of
mid-infrared spectral subspaces for predicting soil properties, Chemometr. Intell. Lab., 153, 92–105,
https://doi.org/10.1016/j.chemolab.2016.02.013, 2016. a, b, c, d
Six, J., Frey, S. D., Thiet, R. K., and Batten, K. M.: Bacterial and Fungal
Contributions to Carbon Sequestration in Agroecosystems, Soil
Sci. Soc. Am. J., 70, 555–569,
https://doi.org/10.2136/sssaj2004.0347, 2006. a
Soares, M. R. and Alleoni, L. R. F.: Contribution of Soil Organic Carbon
to the Ion Exchange Capacity of Tropical Soils, J.
Sustain. Agr., 32, 439–462, https://doi.org/10.1080/10440040802257348, 2008. a
Stenberg, B. and Rossel, R. A. V.: Diffuse Reflectance Spectroscopy for
High-Resolution Soil Sensing, in: Proximal Soil Sensing, edited
by: Rossel, R. A. V., McBratney, A. B., and Minasny, B., Progress in Soil
Science, Springer Netherlands, 29–47,
https://doi.org/10.1007/978-90-481-8859-8_3, 2010. a
Stevens, A., Nocita, M., Tóth, G., Montanarella, L., and van Wesemael, B.:
Prediction of Soil Organic Carbon at the European Scale by
Visible and Near InfraRed Reflectance Spectroscopy, PLoS ONE, 8,
e66409, https://doi.org/10.1371/journal.pone.0066409, 2013. a, b
Syers, J. K., Campbell, A. S., and Walker, T. W.: Contribution of organic
carbon and clay to cation exchange capacity in a chronosequence of sandy
soils, Plant Soil, 33, 104–112, https://doi.org/10.1007/BF01378202, 1970. a
Vagen, T.-G., Shepherd, K. D., Walsh, M. G., Winowiecki, L., Desta, L. T., and
Tondoh, J. E.: AfSIS technical specifications: Soil Health
Surveillance, available at:
http://www.worldagroforestry.org/sites/default/files/afsisSoilHealthTechSpecs_v1_smaller.pdf (last access: 1 October 2021),
2010. a
Viscarra Rossel, R., Behrens, T., Ben-Dor, E., Brown, D., Demattê, J.,
Shepherd, K., Shi, Z., Stenberg, B., Stevens, A., Adamchuk, V., Aïchi, H.,
Barthès, B., Bartholomeus, H., Bayer, A., Bernoux, M., Böttcher, K.,
Brodský, L., Du, C., Chappell, A., Fouad, Y., Genot, V., Gomez, C.,
Grunwald, S., Gubler, A., Guerrero, C., Hedley, C., Knadel, M., Morrás, H.,
Nocita, M., Ramirez-Lopez, L., Roudier, P., Campos, E. R., Sanborn, P.,
Sellitto, V., Sudduth, K., Rawlins, B., Walter, C., Winowiecki, L., Hong, S.,
and Ji, W.: A global spectral library to characterize the world's soil,
Earth-Sci. Rev., 155, 198–230, https://doi.org/10.1016/j.earscirev.2016.01.012,
2016. a
Viscarra Rossel, R. A., Walvoort, D. J. J., McBratney, A. B., Janik, L. J., and
Skjemstad, J. O.: Visible, near infrared, mid infrared or combined diffuse
reflectance spectroscopy for simultaneous assessment of various soil
properties, Geoderma, 131, 59–75, https://doi.org/10.1016/j.geoderma.2005.03.007,
2006. a, b
Wawire, A. W., Csorba, Á., Kovács, E., Mairura, F. S., Tóth, J. A.,
and Michéli, E.: Comparing Farmers' Soil Fertility Knowledge Systems and
Scientific Assessment in Upper Eastern Kenya, Geoderma, 396, 115090,
https://doi.org/10.1016/j.geoderma.2021.115090, 2021. a
Wold, S., Martens, H., and Wold, H.: The Multivariate Calibration Problem in
Chemistry Solved by the PLS Method, in: Matrix Pencils, edited by:
Kågström, B. and Ruhe, A., Vol. 973, Springer Berlin
Heidelberg, 286–293, https://doi.org/10.1007/BFb0062108, 1983.
a
Wold, S., Johansson, E., and Cocchi, M.: PLS-partial least squares
projections to latent structures, 3D QSAR in drug design, Springer Netherlands, 1, 523–550, https://doi.org/10.1007/0-306-46858-1, 1993. a
Short summary
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.
This work delivers openly accessible and validated calibrations for diagnosing 26 soil...
