Soil C sequestration in relation to
environmental footprints:
A snaphot of activities at ILRI’s Mazingira Centre
L. Merbold, K. Butterbach-Bahl, J.P. Goopy, D. Korir, P. Mutuo, F.
Njenga, D.E. Pelster, G.N. Wanyama and the Mazingira Team
CCAFS webinar ”soil carbon and climate change mitigation in the CGIAR”
19.06.2017

Mazingira Centre activities
(fully operational since summer 2015,strongly supported by KIT, Germany)
Vision:
• to test and develop management
strategies that increases livestock, feed
and crop production, while decreasing
GHG emissions and environmental
degradation (ie SOC losses)
11

Case study 1: Water harvesting systems &
consequences for SOC
What do we do? - 2 Case Studies
Saiz et al. 2016, Geoderma,
F. Wandera CLIFF fellow 2015
Wote, Makueni,
CCAFS benchmark site
Largest org. C found in the trenches
Water harvesting system (SWC Ag) better than conventional
Ag but natural vegetation stores largest C

Case study 2: GHG emissions and SOC stocks from long-term (13yrs) maize trail
in Central Kenya (Embu)
What do we do? - 2 Case Studies
J. Macharia CLIFF fellow 2017
S/NO TREATMENT TYPE
1 Control Control
2 Fertilizer (30kg/N) Inorganic
3 Fertilizer (60kg/N) Inorganic
4 Fertilizer (90kg/N) Inorganic
5 Lantana 1/2 Fert 1/2 Organic_Inorganic
6 Lantana full rate Organic
7 Manure 1/2 Fert 1/2 Organic_Inorganic
8 Manure full rate Organic
9 Mucuna Organic
10 Mucuna Fertilizer Organic_Inorganic
11 Tithonia 1/2 Fert 1/2 Organic_Inorganic
12 Tithonia full rate Organic
List of the maize cultivation treatments found in Embu

What do we do?
J. Macharia CLIFF fellow 2017
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05/01/2017 25/01/2017 14/02/2017 06/03/2017 26/03/2017 15/04/2017 05/05/2017 25/05/2017 14/06/2017
CO2Flux(mg C m2h-1)
Sampling date
Control
Fert
Manure
Man + Fert
Preliminary CO2 fluxes from the four investigated treatment: (blue = control, red = 60 kg N inorganic,
green = 90 kg N manure, purple = 45 kg N inorganic, 45 kg N manure)
• Initial C stocks are available (2004), new soils have been collected (2017)

SOC, some important facts
• Soil organic carbon (SOC, measurable part of soil organic matter) plays a crucial role
in nutrient cycling in soils, affecting soil fertility etc.
• Changes in SOC occur for various reasons, ie. land use, land use change etc.
• Natural changes in SOC via inventories are difficult to
determine
• Proxies can be measurements of C exchange (fluxes)
• Inventories are necessary for the baseline
• Continuous observations of C exchange can help to identify
changes in SOC stocks
• Models can work if land use history data is available
Schrumpf et al. 2011, Biogeosciences

This presentation is licensed for use under the Creative Commons Attribution 4.0 International Licence.
better lives through livestock
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ILRI thanks all donors and organizations who globally supported its work through their contributions
to the CGIAR system
Thank you for your attention. Questions?
The Mazingira Team in November 2016, more info under mazingira.ilri.org