Soil organic matter (SOM) concentration and composition are essential properties that affect most functions and ecosystem services. The relationship between soil and environmental covariates regarding SOM concentration and composition in various pools is not completely understood. This study aimed to identify the most influential drivers of SOM stabilization, focusing on arable lands in Hungary. Hungary is an ideal area for investigating SOM variability because it is at the meeting point of the three main climate effects that trigger a wide range of soil, land use, and topographical conditions. Overall, 87 soil samples were taken from the topsoil (2–20 cm) and fractionated (<20 µm) to separate the mineral phase-associated organic carbon (MAOC) and bulk pools. MAOC concentration varied on a wide range (0.5–14.1 %) and was the function of bulk SOM aromaticity and slope steepness, rather than land use, climatic conditions, or soil properties, indicating that MAOC is also affected by decomposition if the bulk OM is less available for the microbiome. Land use, especially in forest topsoils, reflects the elemental composition of the OM, focusing on the variations of residue composition. In contrast, aromaticity is rather related to soil and climate properties, suggesting increased relevance of transformation processes. As a consequence, SOM composition varies on a wide range in the topsoil, however, the lack of a definite trend at the county level suggests the complexity of the system and highlights the role of local circumstances.

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The main objective of the research was to study the environmental "price" of the large-scale, milk production from a rarely known perspective, from the mapping of the estrogenic footprint (the amount of oestrus-inducer hormonal products, and the generated endoestrogens) in the resulting slurry in a dairy cow farm. These micropollutants are endocrine-disrupting chemicals (EDCs) and can be dangerous to the normal reproductive functions even at ng/kg concentration. One of them, 17ß-estradiol, has a 20,000 times stronger estrogenic effect than bisphenol-A, a widely known EDC of industrial origin. While most studies on EDCs are short-term and/or laboratory based, this study is longitudinal and field-based. We sampled the slurry pool on a quarterly basis between 2017 and 2020. Our purpose was testing the estrogenic effects using a dual approach. As an effect-based, holistic method, we developed and used the YES (yeast estrogen screen) test employing the genetically modified Saccharomyces cerevisiae BJ3505 strain which contains human estrogenic receptor. For testing exact molecules, UHPLC-FLD was used. Our study points out that slurry contains a growing amount of EDCs with the risk of penetrating into the soil, crops and the food chain. Considering the Green Chemistry concept, the most benign ways to prevent of the pollution of the slurry is choosing appropriate oestrus-inducing veterinary pharmaceuticals (OIVPs) and the separation of the solid and liquid parts with adequate treatment methods. To our knowledge, this is the first paper on the adaptation of the YES test for medicine and slurry samples, extending its applicability. The adapted YES test turned out to be a sensitive, robust and reliable method for testing samples with potential estrogenic effect. Our dual approach was successful in evaluating the estrogenic effect of the slurry samples.