A new international study co-authored by Kitti Balog and Gábor Szatmári, researchers at the HUN-REN ATK Institute for Soil Sciences, has been published in the Geoderma journal in collaboration with eight universities and research institutions. The study aims to map the spatial distribution of soil salinity on a large scale to support sustainable soil management in Europe. The research focuses on mapping the saturated soil-paste electrical conductivity (EC_e) of European soils using pedotransfer functions and the Quantile Regression Forests machine-learning algorithm.

The study is based on the LUCAS 2018 soil monitoring database, which includes nearly 20,000 topsoil samples. The findings show that EC_1:5, the electrical conductivity of a 1:5 soil-to-water suspension, can be converted to EC_e based on soil texture and soil organic carbon content. The final model performance (R² = 0.302, RMSE = 0.265 dS*m-¹) aligns with similar large-scale studies in the literature. The mapping results reveal that in Northern and Atlantic Europe, salt accumulation occurs through natural processes, while in Mediterranean and Southern regions, human activities—such as irrigation, poor drainage, and seawater intrusion in coastal areas—play a major role.

The study highlights elevated EC_e levels in Spain, which may pose a risk to the productivity of irrigated agricultural soils. Soil salinity monitoring is crucial for achieving the goals of the European Union’s Green Deal and the ’Farm to Fork’ strategy, which aim to ensure sustainable food security. The study’s findings contribute to EU soil degradation monitoring efforts and support policy decision-making. This research was conducted through international collaboration, led by the JRC European Commission, with contributions from researchers at the HUN-REN ATK Institute for Soil Sciences, University College London, CSIC Centro de Investigaciones sobre Desertificación-CIDE Valencia, Aarhus University, TEAGASC (Dublin), Agricultural University of Athens, Isparta University of Applied Sciences, and University of Palermo.

Schillaci C, Scarpa S, Yunta F, Lipani A, Visconti F, Szatmári G, Balog K et al. 2025. Empirical estimation of saturated soil-paste electrical conductivity in the EU using pedotransfer functions and Quantile Regression Forests: A mapping approach based on LUCAS topsoil data. Geoderma 454, 117199. https://doi.org/10.1016/j.geoderma.2025.117199.