I first would like to thank those in the union of these categories, first and foremost my supervisors Sjoerd van der Zee, Jannes Stolte and Coen Ritsema. The news about Sjoerd's passing came during the last stages of writing. He has not only given me the opportunity to start the trajectory, but has maintained a level of confidence in a successful conclusion throughout many years of delay and, at times, stagnation. Sjoerd's criticism has sharpened my writing by patiently pointing out unjustified shortcuts in definitions and descriptions. In the course of the years, this has also shaped my ability to think about research. I see this as a gift that I will cherish throughout my career. Jannes has also shown me patience and confidence. To him I owe the opportunity to be part of a group of people with a drive to study erosion in Norway. Without Jannes' continuous effort to keep me on the straight and narrow, my tendency to get involved in other projects would have made completion of this thesis utterly impossible. I thank Prof. Coen Ritsema for his encouragement and guidance, especially during the phase leading up to the final manuscript and the public defense. I want to thank Prof. Leo Stroosnijder who, after an absence of many years, called me back to Wageningen and recommended my candidature to Sjoerd. Dr. Geert Sterk passed away in 2022, much too early. He was my MSc. supervisor in 2001 and to him I owe thanks because of the confidence he showed in my suitability for a PhD. trajectory. I thank Dr. Manuel Seeger for the support and inspiration during the period in which he was my co-supervisor in Wageningen. The realisation of being a pupil is an experience that is as humbling as it is uplifting, and I want to mention two teachers. To Meester Hoekstra, my fifth grade primary school teacher, I owe the fascination for soil-water-plant interactions. I see this dissertation as the completion of an education that started in the school vegetable garden. To Dr. Hans Schiere, I owe the joy of looking at a problem from a different angle and the realisation that individual choices are not quite so independent from the larger scheme of things. My parents, Jan en Nelly Barneveld, have continuously shown me confidence while making the Big Choices in life. This means especially much because my choices lead on a path that was sometimes difficult to explain (I could have tried a bit harder at times). Pa en ma; dank jullie voor alles (en dat is een hoop). Clarieke, Otto, Ivar, Johan en Aage have always come in the first place. But my inability to strike a balance has, at times, resulted in me being physically present, but not mentally. I thank the five of you for keeping up with this, and even more so for tolerating the Long Explanations that I made you, and will continue to make you, suffer about subjects that are as alien to you as Minecraft is to me. The list of colleagues that have contributed implicitly or explicitly is too long to include here, but I call out to (in alphabetical order) Atilla, Csilla, Dominika, Hannah, Johanne...