Knowledge gap on the spatial structure of soil nitrogen mineralization variability—A systematic review

Abstract

Soil nitrogen (N) mineralization governs plant‐available N from soil organic matter and microbial turnover, and is typically estimated as potentially mineralizable nitrogen (PMN) via anaerobic incubations or as N ₀ and mineralization rate ( k ) via long‐term aerobic incubations. While these metrics are well studied, their spatial variability and spatial structures (spatial dependence and semivariogram parameters) appear absent in scientific literature. We conducted a systematic review using the Web of Science to identify relevant information on this topic. We examined 140 peer‐reviewed publications (1991–2024) matching search terms for spatial variability, geostatistics, and soil N mineralization. Our review revealed a substantial knowledge gap: Only one study addressed spatial variability structures of k or N ₀ , and only six reported spatial variability of PMN. Reported spatial dependencies ranged from <2.3  to >470 m, varying by land use and ecosystem. This research gap, particularly for mineralization kinetics, warrants further investigation to inform agricultural and environmental modeling.