Soil, through its various functions, plays a vital role in the Earth's ecosystems and provides multiple ecosystem services to humanity. Pedotransfer functions (PTFs) are simple to complex knowledge rules that relate available soil information to soil properties and variables that are needed to parameterize soil processes. In this paper, we review the existing PTFs and document the new generation of PTFs developed in the different disciplines of Earth system science. To meet the methodological challenges for a successful application in Earth system modeling, we emphasize that PTF development has to go hand in hand with suitable extrapolation and upscaling techniques such that the PTFs correctly represent the spatial heterogeneity of soils. PTFs should encompass the variability of the estimated soil property or process, in such a way that the estimation of parameters allows for validation and can also confidently provide for extrapolation and upscaling purposes capturing the spatial variation in soils. Most actively pursued recent developments are related to parameterizations of solute transport, heat exchange, soil respiration, and organic carbon content, root density, and vegetation water uptake. Further challenges are to be addressed in parameterization of soil erosivity and land use change impacts at multiple scales. We argue that a comprehensive set of PTFs can be applied throughout a wide range of disciplines of Earth system science, with emphasis on land surface models. Novel sensing techniques provide a true breakthrough for this, yet further improvements are necessary for methods to deal with uncertainty and to validate applications at global scale.

Our current information society, populated by increasingly well-informed and critical stakeholders, presents a challenge to both the policy and science arenas. The introduction of the UN Sustainable Development Goals (SDGs) offers a unique and welcome opportunity to direct joint activities towards these goals. Soil science, even though it is not mentioned as such, plays an important role in realizing a number of SDGs focusing on food, water, climate, health, biodiversity, and sustainable land use. A plea is made for a systems approach to land use studies, to be initiated by soil scientists, in which these land-related SDGs are considered in an integrated manner. To connect with policy makers and stakeholders, two approaches are functional. The first of these is the policy cycle when planning and executing research, which includes signaling, design, decision making, implementation, and evaluation. Many current research projects spend little time on signaling, which may lead to disengagement of stakeholders. Also, implementation is often seen as the responsibility of others, while it is crucial to demonstrate – if successful – the relevance of soil science. The second approach is the DPSIR approach when following the policy cycle in land-related research, distinguishing external drivers, pressures, impact, and responses to land use change that affect the state of the land in the past, present, and future. Soil science cannot by itself realize SDGs, and interdisciplinary studies on ecosystem services (ESs) provide an appropriate channel to define contributions of soil science in terms of the seven soil functions. ESs, in turn, can contribute to addressing the six SDGs (2, 3, 6, 12, 13, and 15) with an environmental, land-related character. SDGs have a societal focus and future soil science research can only be successful if stakeholders are part of the research effort in transdisciplinary projects, based on the principle of time-consuming "joint learning". The internal organization of the soil science discipline is not yet well tuned to the needs of inter- and transdisciplinary approaches.