West African farmers are exposed to a variety of risks, including climate variability. Moreover, trends of population growth, declining natural resources and climate change increase the probability of hazards and extreme events. In this environments, farmers are often struggling to be food selfsufficient or escape poverty. We focused on the area of Koutiala, southern Mali, as an illustrative region for the challenging farming conditions in West Africa.The aim of this thesis was to understand farmers' strategies to cope within a variable and hazardous environment. A parallel objective was to analyse which sustainable intensification options could increase productivity and/or reduce risks within the socio-economic and biophysical context. Risk was defined as the combination of the probability of a hazard taking place and the impact this induces. To analyse risk perception and suitability of on-farm options several data sources were combined: responses from individual surveys and focus group discussions, outputs from crop model simulations, long-term weather data and evaluations of trials and try-out fields embedded within a long-term participatory process.Risks related to health of family members were perceived as the highest, followed by risks related to health of livestock. Farmers managed those risks by maintaining flexibility and diversity in the farm management which allowed them to limit the impact and react quickly when hazards happened.Farmers overcame losses by relying on social interactions and using productive assets, e.g. selling cattle. Hence, they lost capital. Within households, differences in risk perception were related to decision-power, not to gender. Between farms, risk perception was related to resource endowment to a limited extent. The frequency and impact on yield of some hazards were quantified using crop simulation data. Weather hazards occurred at least every five years and reduced cereal yields. The impact of hazards on cereal yields (maize, sorghum, millet) interacted with the cereal management (early sowing, increasing N fertilisation and/or introducing a short duration variety). Increasing maize yields through management did not affect relative yield losses in case of hazards. Adapted millet management caused a trade-off between yield and hazard impact. Adapted sorghum management increased yield and mitigated hazard impacts simultaneously. Further, I demonstrated that on-farm diversification of crop land allocation had the potential to increase stability. The combination of cotton and a cereal had a relatively strong stabilisation benefit, as cotton and the cereals responded differently to weather. While the majority of diversification strategies enabled farmers to meet the food sufficiency requirements, farmers had to target combinations with a high mean return and large variability in order to surpass the poverty line. Within this environment, an iterative and participatory co-learning cycle facilitated a learning environment for researchers and farmers. This process yielded a diver...
