Among PhD candidates it is a well-known hypothesis that the acknowledgements are — perhaps together with the propositions and some other personal stuff — the only part of the thesis that is actually read by the majority of the receivers, of which some might be looking for their own name. I wondered if I should facilitate this by putting all the names I want to mention in alphabetical order. Other options are the more usual approach of going from formal to informal connections, or mention everybody to be acknowledged during a more descriptive part of a PhD journey. I chose to group people; as I dealt with (perceived) randomness as study subject while creating this thesis, I used the pseudo-randomness implemented in the programming language R to give some groups — and most names inside groups — a pseudo-random order.

During my PhD time, I had two experiences that made me feel like almost living in a parallel world. The first one was in autumn (that is, autumn according to the Northern hemisphere) 2018, when I was on the other side of the Earth for three months. To be exact: I was in Brisbane (Queensland, Australia) with its sunny weather, well-organised public life, and extremely friendly people everywhere. Thanks to Tom Orton, Diane and all others involved to make this such a wonderful experience! And also thanks to Ecosciences Precinct, part of Queensland Government and the University of Queensland, department of Plant Sciences, for formally making this possible.

The second parallel world experience is at the moment of writing, spring and winter 2020, at home in Wageningen. I don't know how history will name this event; at this moment we call it the ``Corona crisis": almost the whole world, for the first time in over a century, is in some kind of lock-down situation because of a virus. Instead of physically being somewhere in the Gaia building on Wageningen Campus, I am working from home, not allowed to meet anybody face-to-face unless there is a very good reason to do so -- and even then, on a physical distance. I thank my housemates (Loena, Daan, Thijs, Angelica, Cecilia, Luka, Katharina and Maartje) for this both intense and interesting life experience: being almost locked up in the same accommodation for several months. We got to know each other well, and mostly I enjoyed it.

I would like to mention my fellow PhD candidates and postdocs of the SGL chairgroup and/or closely related: Aukjen, Jalal, Femke, Abbey, Yingxia, Chantal, Anatol, Kasia, Anne-Maartje, Marcos, Cynthia, Rafael, Tijn, Alessandro, Rowin, Rocky, Selçuk, Maricke, Luciana, Marijn, Nienke, Noortje, Alexandre, Cindy, Jasper, Simona, Stephan, Bertin and Neymar. Some of you I met only once; one of you I met only once while I was a witnesses on your wedding; with others I shared an office for several years — and thus important parts of our life. Most of you are somewhere in between. Thank you all for being such nice close colleagues, and for the possibility to share experiences, emotions, opinions, courses and nice moments! It is a real pity that in those last half year we didn't have more coffeebreak & roomies' talk. I also want to mention my non-SGL Wageningen PhD colleagues for sharing experiences, for example Roos (Farming Systems Ecology) and Heleen (Animal Production Systems) — the latter I would also like to thank for being one of my paranymphs and proofreading this thesis. Still within the context of Wageningen PhD's, I would like to mention Benjamin and Dainius (both Laboratory of Geo-information Science and Remote Sensing) for smoothly running together the R-user group during several years.

Furthermore, I am also grateful for the insight into being a PhD candidate in a slightly different system, delivered by UK-based PhD candidates Maud and Doris. Also many thanks to you both for the cosiness during my almost yearly visits and the beautiful walks — for example along the many canals in the English Midlands.

I seem to be a person with many extensive but long-term friendships. All of you were interested in my well-being as PhD candidate, and thus I would like to mention — without the intention of being complete: Lianne, Hanna, Mathijs + Marlies, Audrey, Indira, Max, Flora, Eliane, Louise, Marije, Mali, Mark, Edmelia, Hedwig, Solange, Sanne, John and Jasmijn, Marleen, Irene, Kari-Anne, Joanne, Ireen, Annemarie, Jenneke, Hanneke, Karin, Ellen, Thomas, Mirre, Elanka, Caroline, Arta, Maaike, Yvonne, Keri + Johannes, Mieke, Anna, Silvia, Claudia, Boudien, Anne, Lilianne, Chantal, Femke, Anita, Cor + Justine, Anneloes, Carolina and many others. My gratitude goes also to Didi, for being the second proofreader and also for keeping me updated about science in general. Another special thanks goes to Zoë for your continuous support during tough shared life experiences, and for your willingness to be the other paranymph.

I also want to thank my colleagues in the three groups I was part of: the Soil, Geography and Landscape group; ISRIC — World Soil Information; and the Soil, Water and Landuse team of WEnR, for the nice coffee talks and the other social and/or content-wise interactions. On a more formal level, I am also grateful to the mentioned organisations for offering me this PhD in the first place. Thanks to all the others I encountered within Wageningen UR, among others Cor Langeveld, Karel Keesman and Lenny van Bussel.

An important source of support is my family: my parents Rob (unfortunately passed away) and Kitty, my brothers Reinier and Maarten, my sister Heleen and my siblings' numerous offspring. I thank you all for your interest and ideas!

My mental health during my PhD has certainly improved by the organisations I am part of or dealt with, such as the SFO, Idealis and Droevendaal student housing. I am happy with the many nice people I encountered.

Thanks to Martin Knotters, Titia Mulder, Sytze de Bruin and the others involved for making it possible to practise my defence. I also want to express my gratitude to the real opponents, for their time and effort.

Setting deadlines and sticking to those certainly is not my quality within a PhD context. Therefore I admire the patience of my supervisors cq. promotor and co-promotor Gerard Heuvelink and Dick Brus, and in the background Jakob Wallinga in his role as SGL group leader. You kept trust in me and in the final result. This thesis proves your trust to be justified.

Zum Abschluss: Liebe Almuth, vielen Dank für deine Hilfe beim Layout dieser Arbeit! Es ist etwas Besonderes, dass wir uns seit fast 30 Jahren kennen. Wollen wir dem noch mindestens 30 Jahre hinzufügen?