1. UNCCD 2nd Scientific Conference
Economic assessment of desertification, sustainable land management and
resilience of arid, semi-arid and dry sub-humid areas
9 - 12 April 2013 - Bonn, Germany
THU 3.1: Agroecology as a powerfull tool for the developement of drylands?
Managing soil carbon through agro-ecological practices:
a win-win strategy attending both global (fight against climate change) and local problems
(soil degradation)
Martial Bernoux, Tiphaine Chevallier, Jean-Luc Chotte
Functional Ecology & Biogeochemistry of Soils
& Agro-ecosystems
A French Multi-institute Research group based
in Montpellier
www.montpellier.inra.fr/ecosols

2. The dominant vision since
1992 (UNFCCC)
Mitigation
Soil
of
GHG Carbon
GLOBAL Problems/Solutions Actions/Implementations LOCAL

3. It is time to recognize that “soil carbon” is
not just a matter of FOOD
“Mitigation” and “Climate Change” … SECURITY
Increase agronomic productivity POVERTY
ALLEVIATION
Soil Water Control or
fertility retention reversal of UNCCD
degradation
and
Mitigation
Soil Erosion desertification
of trends
GHG Carbon control
In a context of adaptation to global change
increasing resilience and decreasing vulnerability
GLOBAL Problems/Solutions Actions/Implementations LOCAL
How to maximize trade-offs and find synergies

4. Most sequestering practices show synergies with yield increase
Even in drylands were it is most needed!
Regions Sustainable land management Net mitigation potential Average yield
(Moisture categories (1) increase (2)
regime) tCO2-eq /ha /yr1 %
Dry Cool Warm
Agronomy 0.39 0.39 116
Nutrient 0.33 0.33 72*
management
Tillage/residues 0.17 0.35 122
management
Water management 1.14 1.14 92
Agroforestry 0.17 0.35 81
1IPCC (2006), 2 Branca et al. (2013),* considers only organic nutrient
management
But those values are too
“coarse”, need to down
scale…
How to maximize trade-offs and find synergies

5. Available results at finer resolution?
Geographical Distribution of
Carbon Sequestration Estimates
But those values are too
“coarse”, need to down
scale…

6. Available results at finer resolution?
Geographical Distribution of
Carbon Sequestration Estimates
Lowest values!
C market seems (is) inaccessible

7. Carbon market is dead (or nearly)…long live “practices-based” Market
Market based on the impact/result of
the practice / management options Market based on adoption
of sequestering practices
Estimated results Verified result or management options
Soil C Adoption of a practice that
stock stores/preserves carbon
Estimate
measure
time

8. Adoption of a practice that Need more “validation” studies of the practices and
stores/preserves carbon their impacts in terms of soil C sequestration , and
other co-benefits.
Paucity of data for tropical
and, even more, drylands!
200 200
C content variation from (a) Temperate region (b) Tropical region
the control (base 100)
150 150
100 100
50 50
0 0
0 50 100 150 200 250 300 0 50 100 150 200 250
Total input of ramial wood (t DM / ha )
Adapted from Barthès et al. 2010. Effects of ramial wood amendments on crops and soil: A synthesis of experimental results.
Photos © E. Hien Cah. Agric., 19, 280-87 (In French)

9. Fortune cookie message!
“Soil Carbon is at the crossroads of the conventions and scales
and provides multiples benefits”
Soil
GLOBAL LOCAL
Carbon UNCCD
But “Pratices” should be highlighted!

10. Managing soil carbon through agro-ecological practices:
a win-win strategy attending both global (fight against climate change) and local problems (soil degradation)
This presentation was build upon ideas and exchanges from numerous colleagues
and results from research programs, in particular:
http://www.csf-desertification.org/ http://www.rime-pampa.net/
Une Réponse Intégrée Multi-Équipes au
Programme d’Appui Multi Pays pour l’Agro-écologie
Le Comité Scientifique Français de la Désertification
French Scientific Committee on Desertification
CaSA
Réseau « Carbone des Sols pour une agriculture durable en Afrique »
Sociétés Rurales, Environnement, Climat en Afrique de l'Ouest
Network “Soil Carbon for a Sustainable agriculture in Africa”
Rural Societies, Environment, Climate in West Africa
Rede “Carbono dos Solos para uma agricultura Sustentável na Africa”
http://www.ppr-srec.ird.fr/ http://www.reseau-carbone-sol-afrique.org/

11. Managing soil carbon through agro-ecological practices:
a win-win strategy attending both global (fight against climate change) and local problems (soil degradation)
Full report will be soon available on line at http://www.csf-desertification.org/

12. Managing soil carbon through agro-ecological practices:
a win-win strategy attending both global (fight against climate change) and local problems (soil degradation)
http://www.soilcarbon.org.uk