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Estimates of carbon stocks in sandy soils cultivated under local management practices in Senegal’s groundnut basin

DOI:10.1007/s10113-021-01790-2
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Oscar Pascal Malou at UMR 208 PALOC (IRD/MNHN)
Oscar Pascal Malou
  • UMR 208 PALOC (IRD/MNHN)
Patricia Moulin at Institute of Research for Development
Patricia Moulin
Tiphaine Chevallier at Institute of Research for Development
Tiphaine Chevallier
Dominique Masse at Institute of Research for Development
Dominique Masse
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Abstract and Figures

Soil organic carbon (SOC) is essential for the productivity of agroecosystems and for mitigating climate change. Because the SOC contents of sandy soils are usually small, the effects of agricultural management upon SOC stocks in such soils have been insufficiently studied. In West sub-arid Africa, the coarse-textured soils (mostly Arenosols) are diversely managed by smallholders. In this study, we aimed to quantify SOC stocks in cultivated soils of that region, in a context where agricultural practices rely mainly upon organic inputs derived from various integrated crop-livestock systems. SOC stocks were estimated for the 0–30 cm depth in 1,813 plots in Senegal’s groundnut basin. We found that SOC stocks in farmers’ fields varied between 2.3 and 59.8 Mg C ha-1 (mean ± standard deviation, 14.6 ± 0.14 Mg C ha-1). SOC stocks were influenced slightly by soil type, but were only weakly correlated to soils’ clay and silt contents. SOC stocks differed significantly among the three studied village territories due to contrasting livestock-raising systems. Average stocks were significantly higher in plots close to housings (home-fields), which receive larger amounts of organic inputs, than in plots farther from the village (out-fields). Thus, the organic inputs to home-fields improves soil C stocks of these sandy soils in the short term. Innovative agricultural practices in the studied area probably need to target options for managing all fields optimally. Those options will require continuous application of organic products—a measure that will in turn require solutions for improving availability or management of local organic resources.
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ORIGINAL ARTICLE
Estimates of carbon stocks in sandy soils cultivated under local
management practices in Senegal’s groundnut basin
Oscar Pascal Malou
1,2
&Patricia Moulin
1,3
&Tiphaine Chevallier
4
&Dominique Masse
4,5
&Jonathan Vayssières
1,6,7,8
&
Ndèye Yacine Badiane-Ndour
1,9,10
&Laure Tall
1,9
&Abou Thiam
2
&Lydie Chapuis-Lardy
1,4
Received: 30 June 2020 / Accepted: 14 May 2021
#The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2021
Abstract
Soil organic carbon (SOC) is essential for the productivity of agroecosystems and for mitigating climate change.
Because the SOC contents of sandy soils are usually small, the effects of agricultural management upon SOC stocks
in such soils have been insufficiently studied. In West sub-arid Africa, the coarse-textured soils (mostly Arenosols) are
diversely managed by smallholders. In this study, we aimed to quantify SOC stocks in cultivated soils of that region, in a
context where agricultural practices rely mainly upon organic inputs derived from various integrated crop-livestock
systems. SOC stocks were estimated for the 0–30 cm depth in 1,813 plots in Senegal’s groundnut basin. We found
that SOC stocks in farmers’fields varied between 2.3 and 59.8 Mg C ha
-1
(mean ± standard deviation, 14.6 ± 0.14 Mg C
ha
-1
). SOC stocks were influenced slightly by soil type, but were only weakly correlated to soils’clay and silt contents.
SOC stocks differed significantly among the three studied village territories due to contrasting livestock-raising systems.
Average stocks were significantly higher in plots close to housings (home-fields), which receive larger amounts of
organic inputs, than in plots farther from the village (out-fields). Thus, the organic inputs to home-fields improves soil
C stocks of these sandy soils in the short term. Innovative agricultural practices in the studied area probably need to
target options for managing all fields optimally. Those options will require continuous application of organic products—
a measure that will in turn require solutions for improving availability or management of local organic resources.
Keywords Soil organic carbon (SOC) .SOC stocks .West Africa .Organic input .Coarse texture .Visible near-infrared
spectroscopy
This article is part of the Topical Collection on Regional management
practices with positive effects on soil carbon to meet the goals of the
4p1000 initiative
Communicated by Lydie-Stella Koutika and accepted by Topical
Collection Chief Editor Christopher Reyer
*Oscar Pascal Malou
opmalou@gmail.com
1
LMIIESOL,Dakar,Senegal
2
University Cheikh Anta Diop, Institute of Environmental Sciences,
Dakar, Senegal
3
IRD, IMAGO LAMA, Dakar, Senegal
4
IRD, Eco&Sols, University of Montpellier, CIRAD, INRAE, IRD,
Institut Agro, Montpellier, France
5
IRD, Eco&Sols, Abidjan, Ivory Coast
6
CIRAD, UMR SELMET, Montpellier, France
7
SELMET, University of Montpellier, CIRAD, INRAE, IRD, Institut
Agro, Montpellier, France
8
PPZS,Dakar,Senegal
9
ISRA, LNRPV, Dakar, Senegal
10
Present address: FAO Regional Office, Dakar, Senegal
https://doi.org/10.1007/s10113-021-01790-2
/ Published online: 8 June 2021
Regional Environmental Change (2021) 21: 65
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
ResearchGate has not been able to resolve any citations for this publication.
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Promoting “4 Per Thousand” and “Adapting African Agriculture” by south-south cooperation: Conservation agriculture and sustainable intensification
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Modélisation multi-agents et pluri-niveaux de la réorganisation du cycle de l’azote dans des systèmes agro-sylvo-pastoraux en transition - Le cas du bassin arachidier au Sénégal
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The Rock-Eval® signature of soil organic carbon in arenosols of the Senegalese groundnut basin. How do agricultural practices matter?
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Inorganic fertilizer use efficiency of millet crop increased with organic fertilizer application in rainfed agriculture on smallholdings in central Senegal
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The future of West Africa depends on the capacity of its agriculture to ensure the food security of the population, which should double in the next 20 years, while facing up to the new risks resulting from climate warming. Indeed, the changes in temperature and precipitations already operating and that should become more marked will have serious effects on agricultural production and water resources in this part of Africa in the near future. One of the keys to meeting this new challenge is the adaptation of rural societies to climate risks. To gain better knowledge of the potential, processes and barriers, this book analyses recent and ongoing trends in the climate and the environment and examines how rural societies perceive and integrate them: what are the impacts of these changes, what vulnerabilities are there but also what new opportunities do they bring ? How do the populations adapt and what innovations do they implement - while the climate-induced effects interact with the social, political, economic and technical changes that are in motion in Africa ? By associating French and African scientists (climatologists, agronomists, hydrologists, ecologists, demographers, geographers, anthropologists, sociologists and others) in a multidisciplinary approach, the book makes a valuable contribution to better anticipation of climatic risks and the evaluation of African societies to stand up to them.
The 4p1000 initiative: Opportunities, limitations and challenges for implementing soil organic carbon sequestration as a sustainable development strategy
Article
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Climate change adaptation, mitigation and food security may be addressed at the same time by enhancing soil organic carbon (SOC) sequestration through environmentally sound land management practices. This is promoted by the ‘‘4 per 1000’’ Initiative, a multistakeholder platform aiming at increasing SOC storage through sustainable practices. The scientific and technical committee of the Initiative is working to identify indicators, research priorities and region-specific practices needed for their implementation. The Initiative received its name due to the global importance of soils for climate change, which can be illustrated by a thought experiment showing that an annual growth rate of only 0.4% of the standing global SOC stocks would have the potential to counterbalance the current increase in atmospheric CO2. However, there are numerous barriers to the rise in SOC stocks and while SOC sequestration can contribute to partly offsetting greenhouse gas emissions, its main benefits are related to increased soil quality and climate change adaptation. The Initiative provides a collaborative platform for policy makers, practitioners, scientists and stakeholders to engage in finding solutions. Criticism of the Initiative has been related to the poor definition of its numerical target, which was not understood as an aspirational goal. The objective of this paper is to present the aims of the initiative, to discuss critical issues and to present challenges for its implementation. We identify barriers, risks and trade-offs and advocate for collaboration between multiple parties in order to stimulate innovation and to initiate the transition of agricultural systems toward sustainability. Keywords Carbon sequestration � Climate change