Like in any other part of the country, land degradation resulting from water erosion and nutrient depletion is one of the most challenging problems for farmers in the Central Rift Valley (CRV) of Ethiopia. Nevertheless, investments in land management to reduce land degradation and increase agricultural production by smallholder farmers have been limited. In addition, public and private sector organizations have never collaborated to stimulate (investments in) land improvement. This study focuses on coinvestments, which are conceived as the collaboration of different stakeholders in land management in the form of material, labour, finance, technology, knowledge and governance. The overall aim of this study was to explore the potential of co-investments to foster land management and increase land productivity in the CRV of Ethiopia. Chapter 2 presents farmers’ perceptions of crop productivity and their strategies to cope with perceived changes in the CRV of |Ethiopia. It reveals that farmers perceive a decrease in crop productivity and food production over the last decades and that they blame a decline in rainfall for this. As a consequence, farmers apply different strategies to cope with, and adapt to perceived rainfall shortages and related expected yield losses. However, an analysis of rainfall data in the CRV shows that rainfall characteristics have not changed over the last three decades. Moreover, according to analysis of official data, crop productivity per hectare in the CRV even shows a slight increase over the last decade. Therefore, farmers’ perception of a decline in crop productivity and rainfall can be explained by i) the increased demand to grow more crops to feed the rapidly growing population, and ii) the lower moisture availability for plant growth as a consequence of more intensive farming (often on less suitable fields) and land degradation. The root causes of frequent food shortages are thus not only related to rainfall, but also to soil fertility decline, soil erosion and lack of rainwater storage in the soil. Current farmers’ strategies are, therefore, not adequate to cope with the increased food demand. There is an urgent need to invest in sustainable land management (SLM) practices that enhance local food production. Chapter 3 focuses on the farmers’ perception of land degradation (especially soil erosion and nutrient depletion) and their investments in land management. If farmers perceive land degradation as a problem, the chance that they invest in land management measures will be enhanced. Results reveal that land degradation in the form of water erosion and fertility depletion is a problem and has increased over the last decade in the CRV. Farmers are aware of it and consider it as a problem. Nevertheless, farmers’ investments to control water erosion and soil fertility depletion are very limited. Results also show that farmers’ awareness of both water erosion and soil fertility decline as a problem is not significantly associated with their investments in land management. Hence, even farmers who perceive land degradation on their fields and are concerned about its increase over the last decade, do not significantly invest more in water erosion and soil fertility control measures than farmers who do not perceive these phenomena. Chapter 4 is devoted to exploring the determents of farmers’ decisions how much and where to invest in land management. The study identified five major factors that influence farmers’ decisions how much to invest in land management. These include households’ resource endowments, farming experience and knowledge, access to information, social capital and availability of family labour. This result implies that extension strategies aiming at sustainable land management should try to enhance households’ resources endowments, improve their access to information and stimulate collective action in land management. Similarly, the study revealed the decisions of farmers’ where to invest in land management is influenced by the vulnerability, accessibility and fertility condition of their plots. Farmers were more willing to invest in plots that are vulnerable to water erosion, have better soil fertility and are larger. However, the influence of all these factors on farmers’ investments in land management was highly variable across the different study sites within the CRV. Hence, the diversity in social, economic, cultural and biophysical conditions must be taken into account by rural extension programmes. This calls for site-specific land management strategies that can be planned and implemented at micro-level with active participation of farmers. Chapter 5 deals with co-investments in land management. Lack of collaboration is a growing concern for the success of SLM in Ethiopia. In Ethiopia, not only farmers but also public institutions and private sectors are hesitant to collaborate and invest in SLM. This study identified several major bottlenecks and requirements for co-investments by public institutions and private sectors. Nevertheless, the results varied across the administrative levels. As a result, macro level institutions did not acknowledge most of the bottlenecks and requirements reported by meso and micro level institutions. Therefore, a micro-mesomacro consensus is required to improve co-investments. Furthermore, most bottlenecks and requirements for public institutions were related to governance issues. This suggests the need to establish good governance at all levels in Ethiopia in order to improve co-investments in SLM. In addition to public institutions, private sectors identified major bottlenecks and requirements which are mostly related to economic issues. However, given the current socio-economic and political situation in Ethiopia, it is a long way to fulfilling the requirements proposed by public institutions and private sectors. This indicates that requirements should be fulfilled gradually and systematically for successful co-investments in SLM. Chapter 6 explores the potential of co-investments in land management for bringing change at the grassroot level in Ethiopia. First, this study explores the most important co-investment activities that trigger farmers to invest in land management based on a co-investment initiative in the Galessa watershed. Second, it assesses the impact of these co-investment activities on farmers’ investments in land management by comparing experimental (participant) and control (non-participant) groups of farmers using survey data. The case study revealed that the most important co-investment activities that triggered farmers to invest in land management include co-investments in awareness creation, water provision, technology and governance. Of these activities, co-investing in water provision is the most successful activity, because it directly solves one of the basic needs of farmers in the watershed. Results reveal that the experimental group of farmers invested more in land management practices, such as soil bunds, compost and tree planting, than the control group of farmers. The article concludes that multiple level coinvestment activities are crucial to trigger farmers to invest in land management in Ethiopia. Chapter 7 is a synthesis of previous chapters. It briefly summarizes answers to the research questions, describes the added value of the thesis in terms of knowledge generation and provides suggestions for further research and policy making. The synthesis indicates that although farmers are well aware of the land degradation problem, their investments in land management are not sufficient to reverse the situation. It also reveals that farmers’ investments are affected by highly diverse socio-economic and biophysical constraints. Moreover, public and private sectors are constrained by financial and governance factors and require several preconditions before actually investing in land management. Despite these constraints at micro, meso and macro institutional levels, this thesis shows that there is potential for coinvestments in SLM in Ethiopia. Exploiting this potential principally requires commitment of all stakeholders to co-invest in land management.