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A laboratory exercise was developed for the study of the effect of three cations (Al, Ca, and Na) on the flocculation and dispersion of soil particles. The exercise was designed for Soil Science undergraduate students in the second-course in the Agricultural Engineering and Environmental Sciences department at the University of Vigo. The students' exercise consisted of the addition of different concentrations of NaCl, CaCl[subscript 2], or AlCl[subscript 3] to a kaolinite water suspension and to an agricultural soil water suspension (a more complex system). The most relevant results showed that for the same cation concentration (equiv L-1), the effects on increased flocculation of colloidal material followed the sequence Al > Ca > Na, for both kaolinite and agricultural soil; that is, aluminum is the cation with the highest flocculation capacity, while Na is the cation with the lowest one. These differences are important for the sustainability of agricultural soils, since flocculation in soil systems is a key factor to sustain a suitable soil structure, and therefore, for suitable air and water fluxes in soils. Moreover, the differences in flocculation capacities of different cations should be taken into account in the fertilization programs during the selection of fertilizers (in relation to composition), in order to avoid irreversible problems for the soil structure. The experimental results obtained by students were highly satisfactory, showing experimental values similar to those previously found by the teachers. According to postlab surveys, the students were highly satisfied and in favor of the laboratory exercise developed from both sides, the didactic point of view and the importance of the exercise for the understanding of soil science concepts.

In northern Spain and elsewhere in the world, many vineyards are located on steep slopes and are susceptible to accelerated soil erosion. Contaminants, notably Cu, originating from repeated application of copper-based fungicides to the vines to prevent mildew, are transported and stored in the sediments deposited close to valley bottoms. In this study, the contents and distribution of Cu in 17 soil samples and 21 sediment samples collected from vineyard stands were determined. In addition, the effect of pH on Cu release from vineyard soils and sediments was quantified. The total Cu content (CuT) in the soils varied between 96 and 583 mg kg−1, and was between 1.2 and 5.6 times greater in sediment samples. The mean concentration of potentially bioavailable Cu (CuEDTA) in the sediments was 199 mg kg−1 (46% of CuT), and was 80 mg kg−1 (36% of CuT) in the soils. Copper bound to soil organic matter (CuOM) was the dominant fraction in the soils (on average, 53% of the CuT), while in sediment samples CuOM values varied between 37 and 712 mg kg−1 and were significantly greater ( P < 0.01) than in the soils. Copper associated with non-crystalline inorganic components (CuIA) was the second most important fraction in the sediments, in which it was 3.4 times greater than in the soils. Release of Cu due to changes in the pH followed a U-shaped pattern in soils and sediments. The release of Cu increased when the pH decreased below 5.5 due to the increased solubility of the metal at this pH. When the pH increased above 7.5, Cu and organic matter were released simultaneously. [ABSTRACT FROM AUTHOR]

The article presents information on a study which determined the content and distribution of copper in the surface horizons of young, old and abandoned vineyard soils from the Monterrei designation of origin located in Spain and assessed the effect of changes in land use on copper distribution. The prevalence of copper bound to the organic fraction decreases the adverse environmental effects of this metal on soil organisms and plants. However, some management practices such as organic matter addition or liming should be implemented in order to delay or avoid soil degradation in young vineyards. The influence of new land uses on potential copper mobilization necessitates careful examination for abandoned vineyards.

The acid soils of Ourense province riverland (Galicia, NW Spain) produce about 50,000 tons of grapes for winemaking. As part of ongoing investigations into fungicide transport in Ourense vineyard soils, the occurrence of several fungicides in such soils was investigated. Soil samples were collected from the inter-row topsoil of a vineyard adjacent to the River Alongos, approximately 15km SW of the main city of Ourense. The vines were grown in sandy loam with moderate organic carbon (OC) content (1–2%). Fungicide residues were measured in vineyard soils and river sediments by solid–liquid extraction followed by gas chromatography with mass spectrometric detection (GC–MSD). Procymidone and cyprodinil occurred at higher levels in river sediments than in the case of fludioxonil, metalaxyl and penconazole. The highest concentrations of procymidone in sediments were still low (29–57μg/kg or ppb) suggesting that no accumulation of these compounds occur. All of them were found at higher concentrations in soil; maxima concentrations were about 1000μg/kg for procymidone and metalaxyl, and about 400μg/kg for cyprodinil, fludioxonil and penconazole. Folpet was never detected (detection limit lower than 2μg/kg) in soil and sediments, suggesting that this fungicide was unstable in such samples. The frequency of fungicide detections in soils can be related to their applications in vineyards and the effect of washing off through vineyard canopy by rainfalls. The results found suggest that the vineyard soils of this region are unlikely to be prone to transport of fungicides, and therefore water supplies in this area are unlikely to be at any significant risk of contamination through viticultural use of these compounds. [Copyright &y& Elsevier]

No abstract available. [ABSTRACT FROM AUTHOR]

This article discusses a study which elucidated the dynamics of atrazine sorption and desorption in acid-surface soils obtained from the plough layer of corn fields in Galicia, Spain. Organic carbon, nitrogen and sulphur contents were examined. Atrazine adsorption by the soils was found to decrease with increasing hydrogen-ion concentration. Copper slightly increased atrazine adsorption. Meanwhile, zinc slightly reduced atrazine adsorption. The adsorption of copper and zinc was severely reduced by the presence of atrazine in the soils.

In the context of the current COVID-19 pandemic, and mostly taking a broad perspective, it is clearly relevant to study environmental factors that could affect eventual future outbreaks due to coronaviruses and/or other pathogenic microorganisms. In view of that, the authors of this manuscript review the situation of SARS-CoV-2 and other main pathogenic microorganisms in the environment, focusing on Galicia and Spain. Overall, in addition to showing local data, it is put in evidence that, summed to all efforts being carried out to treat/control this and any other eventual future epidemic diseases, both at local and global levels, a deep attention should be paid to ecological/environmental aspects that have effects on the planet, its ecosystems and their relations/associations with the probability of spreading of eventual future pandemics., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Mercury content of twelve podzols from NW Spain was studied to elucidate the main soil properties involved in the Hg accumulation of these soils. The highest average Hg concentrations (Hg T ) were found in the Bh and Bs horizons (64 and 105 μg kg -1 ), whereas the lowest occurred in the E horizons (15 μg kg -1 ). Moderate values of Hg T were obtained for the A and C horizons (38 and 52 μg kg -1 ). The Hg enrichment factors revealed that the predominant origin of Hg in these soils is the atmosphere instead of the parent material. As it was shown by the PCA performed (which explained 82% of the variance of the data), the main soil characteristics involved in the pedogenetic processes of the studied podzols are organic matter and Al and Fe compounds. The stepwise linear regressions made described between 54% and 84% of the predicted Hg depending on the soil horizon. Besides a complex ensemble of biogeochemical reactions involved in the balance between input and outputs of Hg, the most influencing variable in the A horizons was organic C, moderate stability Al-humus complexes in the E horizons, Fe-humus complexes and pH w in the Bh horizons, Al-humus compounds in the Bs horizons and crystalline Al and Fe compounds in the C horizons. Therefore, Hg is mobilized from the A and E horizons bound to dissolved organic matter and precipitated in the illuvial horizons due to the saturation of the organic matter with metals. The immobilization of Hg in the subsuperficial horizons of podzols leads to different environmental benefits derived from the removal of Hg from the A horizons, more exposed to climate-induced and land use/cover changes that could potentially modify the dynamics of Hg in those superficial horizons., (Copyright © 2020 Elsevier Inc. All rights reserved.)