Soil literacy as a social dimension of soil security: A multidimensional assessment among Portuguese students

Soil literacy is increasingly relevant to soil security, soil stewardship and sustainable land management, particularly in regions exposed to erosion, drought, wildfire impacts, desertification risk and land-use change. This study assessed soil literacy among school students surveyed in the Porto Metropolitan Area, Portugal, using a multidimensional index-based framework. A cross-sectional survey was administered to third-cycle and secondary students, and 424 valid responses were analysed. Seven dimensions were assessed: soil knowledge, soil functions awareness, soil degradation perception, soil threats recognition, soil protection measures recognition, behavioural awareness and affective-civic orientation. Composite indices were transformed to a common 0–100 scale and psychometrically assessed using internal consistency statistics, corrected item-total correlations and exploratory factor analysis. Group differences were examined using non-parametric tests with false-discovery-rate adjustment, associations among indices using Spearman correlations, and multidimensional profiles using PERMANOVA. The indices showed acceptable to excellent internal consistency, while the Overall Soil Literacy Index was interpreted as a secondary synthesis rather than as a substitute for the component profile. Students obtained higher scores for soil functions awareness, behavioural awareness and recognition of protection measures, but lower scores for soil knowledge, soil degradation perception and affective-civic orientation. PERMANOVA showed statistically significant but small associations between student characteristics and the multivariate soil literacy profile. The results indicate that students recognise soil usefulness more strongly than the processes that generate, transform and degrade it. The study provides a reproducible, psychometrically assessed framework for soil literacy research and identifies regional priorities for locally strengthening soil education as part of soil-security connectivity.