Century-long reconstruction of gridded phosphorus surplus across Europe (1850–2019)

Abstract

Phosphorus (P) surplus in soils significantly contributes to the eutrophication and degradation of water quality in surface waters worldwide. Despite extensive European regulations, elevated P levels persist in many water bodies across the continent. Long-term annual data on soil P surplus (the difference between P inputs and outputs) are essential to understand these levels and guide future management strategies. This study reconstructs and analyzes the annual long-term P surplus for both agricultural and non-agricultural soils from diffuse sources across Europe at a 5 arcmin (≈ 10 km at the Equator) spatial resolution from 1850 to 2019. The dataset includes 48 P surplus estimates that account for uncertainties arising from different methodological choices and coefficients in major components of the P surplus. Our results indicate substantial changes in P surplus magnitude over the past 100 years, underscoring the importance of understanding a long-term P surplus. Specifically, the total P surplus across the EU 27 has tripled over 170 years, from 1.19(±0.28) kg ha−1 of physical area in 1850 to around 2.48(±0.97) kg ha−1 of physical area per year in recent years. We evaluated the plausibility and consistency of our P surplus estimates by comparing them with existing studies and identified potential areas for further improvement. Notably, our dataset supports aggregation at various spatial scales, aiding in the development of targeted strategies to address soil and water quality issues related to P. The P surplus reconstructed dataset is available at https://doi.org/10.5281/zenodo.11351027 (Batool et al., 2024).