In this paper, we present and analyze a novel global database of soil infiltration measurements, the Soil Water Infiltration Global (SWIG) database. In total, 5023 infiltration curves were collected across all continents in the SWIG database. These data were either provided and quality checked by the scientists who performed the experiments or they were digitized from published articles. Data from 54 different countries were included in the database with major contributions from Iran, China, and the USA. In addition to its extensive geographical coverage, the collected infiltration curves cover research from 1976 to late 2017. Basic information on measurement location and method, soil properties, and land use was gathered along with the infiltration data, making the database valuable for the development of pedotransfer functions (PTFs) for estimating soil hydraulic properties, for the evaluation of infiltration measurement methods, and for developing and validating infiltration models. Soil textural information (clay, silt, and sand content) is available for 3842 out of 5023 infiltration measurements (∼ 76%) covering nearly all soil USDA textural classes except for the sandy clay and silt classes. Information on land use is available for 76 % of the experimental sites with agricultural land use as the dominant type (∼ 40%). We are convinced that the SWIG database will allow for a better parameterization of the infiltration process in land surface models and for testing infiltration models. All collected data and related soil characteristics are provided online in *.xlsx and *.csv formats for reference, and we add a disclaimer that the database is for public domain use only and can be copied freely by referencing it. Supplementary data are available at https://doi.org/10.1594/PANGAEA.885492 (Rahmati et al., 2018). Data quality assessment is strongly advised prior to any use of this database. Finally, we would like to encourage scientists to extend and update the SWIG database by uploading new data to it.

Microplastics (MiPs) can potentially influence soil structural stability, with impacts likely dependent on their chemistry, concentration, size, and degradation in soil. This study used high-energy moisture characteristics (HEMC; water retention at matric suctions from 0 to 50 hPa) to quantify the effects of these MiP properties on soil structure stabiltiy. The HEMCs of soil samples contaminated with polypropylene (PP) or polyethylene (PE) were measured and modelled. Greater MiP concentrations (2 % and 7 % w w^-1) increased the volume of drainable pores (VDP). At smaller MiP concentrations (0.5 % and 1 % w w^-1), larger MiP fibres (3 and 5 mm) exhibited higher VDP values compared to a smaller size (1.6 mm) across a range of concentrations. Both PE and PP MiPs increased the modal matric suction (h_modal). The impacts on VDP and h_modal were more pronounced for fast than slow wetting, likely due to MiPs fibres entangling around soil aggregates, and MiPs pores filling after aggregate slaking, respectively. Soil structural index (SI) and stability ratio (SR) values increased following MiP incorporation. Our findings revealed the detrimental impacts of MiPs on soil aggregates and pores, demonstrating that MiPs significantly influence HEMC parameters due to combined impacts on structure stability and pore distribution. ENVIRONMENTAL IMPLICATION: Microplastics have emerged as a major anthropogenic hazardous material in the soil environment, with secondary impacts on soil structure and aggregate stability. Our study indicates that MiPs alter water retention, pore distribution, and soil hydraulic properties, affecting soil's ability to retain and supply water. The introduction of MiPs leads to the destruction of soil aggregates and pores, compromising soil health and productivity. By characterising structural stability and pore structure dynamics using HEMC, this study highlights the sensitivity of MiP impacts, emphasizing the need for comprehensive assessment and strategies to preserve soil ecosystem functioning in the face of increasing MiP pollution.

The impact of heat treatment and wetting–drying cycles on the wetting properties of sandy forest soils was explored. Topsoil and upper subsoil were sampled at three beech forest sites in northern Germany. The air‐dried soils were treated at 20, 40 and 80°C for 24 h, with materials treated at 20°C serving as reference. After wetting, materials were air‐dried or shock‐frozen in liquid N ₂ and freeze‐dried. Interfacial properties were monitored by sessile drop contact angles (CAs) and X‐ray photoelectron spectroscopy (XPS), which provide physical and chemical information on the outermost particle interface layer. CAs of reference samples were around 90° and significantly increased after 80°C‐treatment to >90°, whereas 40°C‐treatment had in comparison to reference soils no distinct impact on CA. Depending on the initial temperature treatment, air‐drying after wetting decreased CA to 60–80% and shock‐freezing and freeze‐drying decreased CA to 10–50% of the reference value. Results suggest that shock‐freezing may preserve the organic matter molecular structure that prevails during contact with water at the solid–liquid interface, thus indicating the wettability of the wet surface. Generally, wetting–drying cycles had the least impact on 80°C‐treated material. XPS analysis confirmed dynamic interfacial molecular restructuring processes by changes in O and C content and the content of non‐polar C compounds. A second heat treatment after two wetting–drying cycles again proved the distinct and pronounced impact of 80°C‐treatment on CA, especially with prior shock‐freezing and freeze‐drying. In conclusion, the findings of our study indicate a sensitive and partly reversible reorganization of the solid interfacial wetting properties. Results may conceptually be used to develop dynamic wettability models, which are needed to simulate the sensitive interplay between wettability and dynamic soil hydraulic functions at sites that are exposed to intensive and periodic moisture fluctuations. Highlights: T > 40°C increased contact angle; after wetting contact angle depended on how the water was removed Shock‐freezing and freeze‐drying preserves contact angle of the wetted state Contact angle changes confirm interface molecular restructuring due to heat treatment or wetting Contact angle change goes along with changes in element content within XPS analysis depth