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Accueil du site → Projets de développement → Projets de recherche pour le Développement → 2017 → Integrated soil fertility management for climate smart intensification of maize-based cropping systems in Kenya

Fonds National Suisse de la Recherche Scientifique (FNSRS) (2017)

Integrated soil fertility management for climate smart intensification of maize-based cropping systems in Kenya

Maize-based cropping systems Kenya

Titre : Integrated soil fertility management for climate smart intensification of maize-based cropping systems in Kenya

Numéro  : 172940

Début/Fin : 01.07.2017 - 30.06.2021

Requérant  : Six Johan ETH Zürich - ETHZ

Partenaire (s) : Int. Institute for Tropical Agriculture IITA

Maize is a staple crop for millions of people in Sub-Saharan Africa (SSA). SSA is the only region in the world where maize yields have annually increased by only 1.2% since the 1960s. The smallholder rain-fed maize production in this region is much less than could be obtained due to soil degradation, declining soil fertility, limited use of inorganic fertilizer, climatic variability and change, and the consequent rise in abiotic and biotic stresses. Hence, there is an urgent need to increase maize production by smallholder subsistence farmers while restoring degraded ecosystems and mitigating climate change. It is, sustainable food security requires socially and environmentally responsible intensification, not extensification, of agriculture. Sustainable intensification management practices, such as integrated soil fertility management (ISFM) practices have been proposed to increase maize yield and soil organic matter (SOM) compared to conventional management practices. However, their potential to increase yield, SOM and reduce soil greenhouse gas (GHG) emissions, and thus contribute to climate change mitigation has not been evaluated at longer temporal and larger spatial scales. It is predicted, and already experienced, that climate change increases the incidence of extreme events such as droughts and prolonged periods of high temperatures in SSA. Effects of ISFM practices on yield and its inter-annual variability under future climatic conditions and thus their future potential as climate-smart agriculture are, however, still uncertain. This proposed modelling project will assess maize intensification through ISFM practices in Kenya. A wide scale adoption of ISFM practices by Kenya’s smallholder farmers requires an evaluation of the biophysical potential of ISFM to increase maize yield, improve soil functions, and mitigate climate change in comparison with conventional soil management practices across all possible combinations of soils and microclimates representative of Kenya’s crop growing environment. Process based modelling allows to account for all possible soil and climate variations in the region to simulate crop yield, and C, N and P exchange between soil and plants and for C and N also with the atmosphere in response to alternative management practices at various spatial and temporal scales. Through spatial modelling with the DAYCENT ecosystem model we propose to (1) assess the biophysical potential of ISFM as a climate-smart agricultural option to enhance maize yield, increase soil C, N and P and reduce soil GHG emissions in comparison with conventional soil management practices at the decadal temporal scale and regional and national spatial scale, (2) identify the ISFM practices (i.e., in terms of organic resource quantity and quality and inorganic fertiliser quantity) that have the highest potential to enhance maize yield and mitigate climate change under specific soil and climatic conditions, (3) elucidate the complex interactive effects between quality and quantity of organic resources, quantity of inorganic fertiliser, and key biophysical drivers, such as inherent soil properties and climate, (4) explore the effects of optimal ISFM practices versus conventional management practices on maize yield and its inter-annual variation at the regional and national level under future climate scenarios in order to assess localized climate change adaptation potentials of ISFM practices. This will enable us to identify ISFM practices that support the highest and most stable maize yield under future climate conditions in different localities across Kenya

Mots clés : soil greenhouse gases, sustainable intensification, biogeochemical modeling, DAYCENT, maize cropping systems, climate smart agriculture

Financement : 332’673.00

Fonds National Suisse de la Recherche Scientifique

Page publiée le 7 septembre 2017, mise à jour le 12 octobre 2017