The excitement I had four years ago when I started the PhD process has come across in this thesis with the help of many people and organizations. I express my earnest gratitude to all of them. I would like to take the pleasure of the completion of my thesis as an opportunity to thank those who made significant contribution to the successful completion of the PhD journey. Foremost, I am deeply thankful to my promotor Prof. Hans van Trijp and co-promotors Dr Paul Ingenbleek and Dr Workneh Kassa. Dear Hans, I am grateful to the freedom you gave me to explain my views during our discussions, and your incisive suggestions and comments that helped me a lot to grow as a researcher. Your approach to simplify theoretical abstraction, to sketch relationship of concepts/ideas in a simply pictorial representation and to keep me lively, enthusiastic and in the same page of our discussions has remained in my mind as a valuable asset. I also greatly appreciate your 'deep reading' approach that leaves no room even for a small spelling error beside to the metacognitive synthesis, reflections and comments. Paul, I immensely thank you for the day-today guidance, follow-ups, constructive criticisms, comments and suggestions. Had it not for your dedicated support, guidance and insightful inputs, it would have never been possible to fruitfully complete the PhD process in four years. At all stages in the course, I benefited from your advice and astute criticisms, particularly so in eyeing concepts at a theoretical landscape and concretization to the real lives and interpretation schemes of the subjects of this PhD research. You have always a way to encourage and remind that a PhD life is a "going-concern" that demands consistent commitment with the hope to achieve the goal in a foreseeable feature. Your phrases 'get out of your comfort zone', 'be strong' and 'good luck' became my dayfares to think strategically, to aim higher and to energize myself to keep the momentum. I really thank you for the dedication and approach you followed to shape me to become a better researcher. Workneh, you have mentored and supported me in my journey since my undergraduate. In the course, you have treated me as a brother and supported me by setting a good example and sharing your experiences that become an instrumental guide to foster my thinking horizons and to systematically manage challenges. I am very much grateful to you for all the advice, support, inspirational discussions and comments. I would like to thank the members of the defence committee Prof. Han van Dijk, Prof. Arjen Wals, Dr Bas Hillebrand and Prof. Belay Kassa for reviewing my thesis and coming to Wageningen for my public defence. It is a great honour for me to have you in my PhD committee. My gratitude also goes to my paranymphs Robert Goedegebure and Falylath Babah Daouda for your support during my preparation for the PhD defence and your friendship during my PhD study. Undertaking this PhD study would have never been possible without the financial support from the Netherlands Organiz...