Advancing urban soil health: challenges, knowledge gaps, and future research perspectives

• Urban soils are under-researched compared to agricultural soils near cities. • Studies focus on topsoil chemistry, ignoring deeper, physical, and biological aspects. • Urban soil health studies are uneven and rarely examine links to human health. • Linking soil experts with urban planners helps guide sustainable city development. • Balanced soil health metrics are key to urban sustainability strategies. Urbanization is projected to surpass 65% of the global population by 2050 and urban soils remain an overlooked yet crucial component for a sustainable development. Here we present an analysis of the current state of research on urban soil health, focusing specifically on soils embedded within strictly urban environments (urban-affected soils). Based on scientific literature review, this study systematically investigates 63 scientific papers published between 2008 and early 2025, examining various aspects of soil health research in urban environment including geographical distribution, land use, sampling depths, and soil health indicators. The results indicate a growing interest in urban soil health, particularly in recent years. The prevalence of research on this topic in specific regions of the world may be the result of the distribution of metropolitan areas, with the consequent enhance of awareness and importance of soil health in those regions. The emphasis on chemical properties, particularly soil contamination, in the literature is consistent with historical trends, while the limited attention given to physical and biological properties calls for a more balanced approach. Ecosystem services, despite their recognized importance, are underutilized, urging a deeper exploration of specific services that contribute directly to human health. Sampling depth at soil profile scale emerged as a crucial factor, with a significant proportion of studies limited to the topsoil at depths of 20 cm or less. Considering the correlation between soil depth and ecosystem services, the findings emphasize the need for future research to explore greater sampling depths for a more comprehensive understanding of urban soil health. Despite the growing interest in the field, urban soil health research remains shallow, both literally and conceptually. This work highlights the need for stronger collaboration between soil scientists and urban stakeholders, such as policymakers, planners, and the citizens. Bridging this communication gap will help shape research agendas and policies that address urban challenges, inform planning, and promote sustainable development.