The African Farming Systems Update Project. Farming systems and food security in Africa: Priorities for science and policy under global change. Technical Annex: FS Characterization with GAEZ Data

In 2012, the government of Australia established the Australia International Centre for Food Security (AICFS) to help achieve food and nutritional security in Africa through the provision of focused research and capacity building. Hosted by the Australian Centre for International Agriculture Research (ACIAR), AICFS research will help boost the productivity and commercial orientation of smallholder agriculture and support the improvement of livelihoods in a sustainable manner. The Centre undertakes medium to long-term end-user driven collaborative agricultural research for development and it develops education and training programs as well as strategies that build innovation and R&D capacity; and deploy research outputs and encourage take up by smallholder farmers. The AICFS research will contribute to informing the agenda for food security in Africa as well as underpin the development of the strategic orientation and program portfolio of AICFS. One of the research foci is the update of earlier farming systems work (Dixon et al 2001) in the African Farming Systems Update Project: “Farming systems and food security in Africa: Priorities for science and policy under global change”. This work aims to fill a current gap for a suitable text on African farming systems for university courses. It will also provide a valuable resource for governments in their efforts to understand and harness the key trends that are expected to influence farming systems evolution over the next fifteen years as well as for academic programs that AICFS plans on developing. A workable number of farming systems was selected for the purpose of targeting policy makers who need relatively large-scale tendencies for planning. Among the 14 systems identified in the 2001 study, thirteen farming systems were defined based on agro-ecological criteria. Farming systems and subsystems definitions and map classes follow a rigorous basis and explicit set of principles. The first principle applied is to have the continental level farming systems map classes align with length of growing period (LGP) boundaries. LGP is a component of agro-ecological zones (AEZs) that include amongst others, climate, soils, terrain and land cover resources inventories. The LGP map used is from the GAEZ version 3.0, released by the International Institute for Applied Systems Analysis (IIASA) and FAO through their GAEZ data portals in May 2012. As a further contribution to the African Farming Systems Update Project, IIASA provided farming system characterizations with biophysical and agronomic GAEZ data. This work is documented in this technical annex

Closing yield gaps: how sustainable can we be?

Global food production needs to be increased by 60-110% between 2005 and 2050 to meet growing food and feed demand. Intensification and/or expansion of agriculture are the two main options available to meet the growing crop demands. Land conversion to expand cultivated land increases GHG emissions and impacts biodiversity and ecosystem services. Closing yield gaps to attain potential yields may be a viable option to increase the global crop production. Traditional methods of agricultural intensification often have negative externalities. Therefore, there is a need to explore location-specific methods of sustainable agricultural intensification. We identified regions where the achievement of potential crop calorie production on currently cultivated land will meet the present and future food demand based on scenario analyses considering population growth and changes in dietary habits. By closing yield gaps in the current irrigated and rain-fed cultivated land, about 24% and 80% more crop calories can respectively be produced compared to 2000. Most countries will reach food self-sufficiency or improve their current food self-sufficiency levels if potential crop production levels are achieved. As a novel approach, we defined specific input and agricultural management strategies required to achieve the potential production by overcoming biophysical and socioeconomic constraints causing yield gaps. The management strategies include: fertilizers, pesticides, advanced soil management, land improvement, management strategies coping with weather induced yield variability, and improving market accessibility. Finally, we estimated the required fertilizers (N, P2O5, and K2O) to attain the potential yields. Globally, N-fertilizer application needs to increase by 45-73%, P2O5-fertilizer by 22-46%, and K2O-fertilizer by 2-3 times compared to the year 2010 to attain potential crop production. The sustainability of such agricultural intensification largely depends on the way management strategies for closing yield gaps are chosen and implemented

RCP 8.5 Ghana. High-end climate change impacts on crop production

Climate change threatens vulnerable communities in sub-Saharan Africa who face significant challenges for adaptation. Agriculture provides the livelihood for the majority of population. High-resolution assessments of the effects of climate change on crop production are urgently needed for targeted adaptation planning. In Ghana, next to food needs, agriculture plays an important role on international cocoa markets. To this end, we develop and apply a National Agro-Ecological Zoning system (NAEZ Ghana) to analyze the impacts of high-end (RCP8.5) global warming on agricultural production potentials until the end of this century. NAEZ Ghana uses an ensemble of the CORDEX Africa Regional Climate Model, a regional soil map, to assess development trends of crop production potentials for 19 main crops. Results highlight differential impacts across the country. Especially due to the significant increase in the number of days exceeding high-temperature thresholds, rain-fed production of several food and export crops could be reduced significantly compared to the historical 30-year average (1981-2010). Plantain production, an important food crop, could achieve under climate change less than half of its current potential already in the 2050s and less than 10% by the 2080s. Suitable areas for cocoa production decrease strongly resulting in only one third of production potential compared to today. Other crops with detrimental effects of climate change include oil palm, sugarcane, coffee, and rubber. Production of maize, sorghum, and millet cope well with a future warmer climate. The NAEZ Ghana database provides valuable high-resolution information to support agricultural sector development planning and climate change adaptation strategies. The expansion of irrigation development will play a central role in some areas. This requires further research on Ghana’s linkages between food, water, and energy, taking into account climate and socio-economic changes