Bolo, Peter Omondi

Gluecks, Ilona V.

Kuntu-Blankson, Kate

Notenbaert, An Maria Omer

Nyawira, Sylvia Sarah

Sommer, Rolf

Tessema, B.

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Notenbaert A, Kuntu-Blankson K, Tessema B, Bolo P, Nyawira S, Gluecks I, Sommer R.International Center for Tropical Agriculture – (CIAT), Tropical Forages Program. Km 17 Recta Cali–Palmira, Colombia.    CONTACT: a.notenbaert@cgiar.orgTowards the quantification of soil organic carbon (SOC) sequestrationpotential in the grasslands of East AfricaThis poster is licensed for use under the Creative Commons Attribution 4.0 International license (CC BY 4.0) 2018-09. Design: JL Urrea (CIAT)This work was undertaken as part of the CGIAR Research Program on Livestock. We thank all donors that globally support our work through their contributions to the CGIAR system.Acknowledgement Poster presented inInternational Conferenceon Agricultural GHG Emissionsand Food Security –Connecting research to policy and practiceBerlin, 10–13 September 2018SOC t/ha43.13 ± 5.28117.2 ± 122.0753.12 ± 28.43101.42 ± 34.2435.87 ± 25.9599.00 ± 59.02CS rates (t C ha-1 y-1)1.77 ± 0.180.77 ± 0.333.07--2.44 ± 2.14CountriesEast AfricaEthiopiaKenyaRwandaTanzaniaUgandaTable 1. Estimated soil C stocks (tonnes ha-1) and sequestration (tonnes ha-1 yr-1) potentials of grasslands in East African countries.Figure1. Simulated SOC trends under different grazing management options over a 20 year period.2018383940412020 2022 2024 2026 2028Years2030 2032 2034 2036 2038SOC stocks (Tonnes C/ha)MF 25% Plant removal + FallowGM 25% Plant removalGL 20% Plant removalIncreaseorganic matter Protectionagainstsoil erosionEfficientnutrient use sequester carbondeeper water infiltrationencouraged by deep rooting grassesGoodbiologicalactivityNKN PPCO2 CO2CO2IntroductionConclusions and recommendationsChallengeSuggested approachThe first resultsThe results so far indicate that reduction of grazing pressure and improved rangeland management are  promising interventions which could result in  SOC sequestration.More robust empirical data is needed to improve the accuracy of SOC modelling efforts in the region.Grasses provide great potential to sequester carbon in soils, due to their fast establishment, growth and biomass production, among other benefits:Grasslands in East Africa cover about 80 million hectares, making it the single biggest land cover in the region with a huge – but as of yet: unquantified – potential for climate change mitigation in the region.A huge knowledge gap exists and there is a need to increase our understanding of the quantitative impact of major drivers of SOC concentrations in grassland soils.As few as 23 studies were found on field estimates of soil C sequestration potentials in the grassland systems in East Africa.  They report a wide range and lots of uncertainty in both SOC stocks (from 3–93 tonnes/ha in the upper 0–30 cm of the soil profiles) and SOC sequestration rates (ranged from as low of 0.1 to as high as 3.1 tonnes/ha/year).Out of 102 articles reviewed on the causes, consequences and remedies for rangeland restoration, 59 focused on Africa. Only 25 of those provide a qualitative estimate on the extent of rangeland degradation and/or rangeland condition while quantitative information about remedies and impacts of such remedies is largely missing.SOC modelling can already enable us to compare alternative management approaches, develop scenario forecasts, and eventually facilitate the scaling-up of observed monitoring and assessment information.Initial runs with the DAYCENT model to investigate the impact of different grazing regimes on SOC in the top 20cm -continuous light grazing; GL (20% removal of plant mass), moderate grazing; GM and moderate grazing with a fallow phase; MF (25% removal of plant mass). After a 20year period of simulation, GM resulted in a 0.3% loss of total SOC, MF increased carbon by 2.4% the initial stock, GL increased SOC by 122 kgC/ha/yr.The considerable technical potential of grassland management practices to realize mitigation at relative low cost warrant its due consideration in climate change mitigation actions. These practices generate additional important co-benefits in the form of food security, biodiversity and water conservation, and improved resilience and thus adaptation to climate change.As the SOC sequestration potential is even higher in degraded soils, a future focus on restoration of grasslands is proposed, to concurrently contribute to climate change mitigation and increase productivity. Burundi 0.86 x 106 haEthiopia 31.6Kenya  20.4Rwanda 0.49Tanzania 22.5Uganda 4.50EKUTRB

Towards the quantification of soil organic carbon (SOC) sequestration potential in the grasslands of East Africa

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Towards the quantification of soil organic carbon (SOC) sequestration potential in the grasslands of East Africa

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