The aim of this work was to evaluate the effects of spent coffee grounds (SCG), a highly hydrophobic raw material, on the hydrophobicity of two Mediterranean agricultural soils. Physical, chemical, mineralogical and biological soil properties, most of them used to evaluate soil quality, were studied and related to the main hydrophobicity parameters. The in vitro assay was performed with two SCG doses (2.5 and 10%), two soils and two incubation times (30 and 60 days). Hydrophobicity was determined by the water drop penetration time test (WDPT), the contact angle (CA) with H₂O, formamide and diiodomethane, and the surface free energy components (SFE) calculated using the Van Oss model. The addition of SCG increased the WDPT, CA and SFE, being the latter which was related to a greater number of soil quality variables. Hydrophobicity was related to lower humus quality index (HQI), and a higher proportion of labile organic matter, as shown by Infrared and UV–vis spectroscopy. An increase in hydrophobicity was related to an improvement of soil physical quality: a high aggregate stability index, saturated hydraulic conductivity, porosity (total and macro), water retention, and a less bulk density. The most critical effect related to the increase in hydrophobicity was the significant decrease in the available water content. The SEM images showed a greater occlusion and stabilization mechanism of the SCG particles incorporated in Vega soil, probably due to its higher content of smectite and carbonates. The appearance of fungal biomineralizations of calcium carbonate is associated with SCG addition and could be considered as an interesting and little studied process of inorganic carbon fixation and secuestration. These results showed that hydrophobicity can afford relevant information that can help to asses soil quality status after an amendment with SCG.

这项工作的目的是评估一种高度疏水性的原料咖啡渣（SCG）对两种地中海农业土壤的疏水性的影响。研究了土壤的物理，化学，矿物学和生物学特性，其中大多数用于评估土壤质量，并与主要的疏水性参数有关。用两种SCG剂量（2.5％和10％），两种土壤和两种孵育时间（30天和60天）进行体外测定。通过水滴渗透时间测试（WDPT），与H ₂的接触角（CA）确定疏水性O，甲酰胺和二碘甲烷，以及使用Van Oss模型计算的表面自由能组分（SFE）。SCG的添加增加了WDPT，CA和SFE，后者是与大量土壤质量变量相关的。疏水性与较低的腐殖质指数（HQI）和较高比例的不稳定有机物有关，如红外和紫外可见光谱法所示。疏水性的增加与土壤物理质量的改善有关：集料稳定指数高，饱和导水率，孔隙率（全部和宏观），保水率和堆积密度较低。与疏水性增加有关的最关键的影响是有效水分的显着减少。SEM图像显示掺入Vega土壤中的SCG颗粒具有更大的吸留和稳定机制，这可能是由于其蒙皂石和碳酸盐含量较高。碳酸钙的真菌生物矿化作用的出现与SCG的添加有关，可以认为是无机碳固定和隔离的有趣且很少研究的过程。这些结果表明，疏水性可以提供相关的信息，有助于SCG改良后评估土壤质量状况。