Mapping Global Nitrogen Mineralization Rates: A Climate-Soil Perspective

The file "Ecosystem_β.tif" represents the spatial distribution of nitrogen mineralization rates in global ecosystems (cropland, grassland, and forest) under different climate models (SSP1-2.6, SSP2-4.5, SSP5-8.5). "Cropland_β.tif" represents the spatial distribution of cropland ecosystems across various SSPβ scenarios. "Grassland_β.tif" represents the spatial distribution of grassland ecosystems under different SSPβ scenarios. "Forest_β.tif" represents the spatial distribution of forest ecosystems across different SSPβ scenarios.

Abstract

Global modeling of soil net nitrogen (N) mineralization rates (Nmin) is challenging due to the absence of an integrated system that accurately quantifies their magnitude and spatial distribution. This study addresses this gap by analyzing the spatial variability of Nmin using a comprehensive dataset of 1,347 N mineralization measurements from 291 studies, combined with high-resolution climate and soil data. Our global maps reveal average Nmin rates of 1.68, 5.17, and 1.71 mg N kg-1 day-1 for cropland, forest, and grassland soils, respectively. Integrating projected climate scenarios, we also explore potential shifts in Nmin patterns under future varying environmental conditions. Key factors influencing Nmin include mean annual precipitation, soil pH, total nitrogen, carbon-to-nitrogen ratio, and microbial biomass nitrogen (MBN), with microbial biomass nitrogen playing a particularly significant role. These findings underscore the potential of global-scale Nmin modeling to support informed decision-making, facilitating optimal fertilizer use and management practices that promote soil health and sustained productivity.