Pedological formations on old mountain geomorphological surfaces of central Spain

The chemo-morphological properties of soils on ancient landforms (quarzitic pliocene alluvial fans, pleistocene terraces), namely "rañizos", on middle-high mountains (Eastern-Central System, Iberian Peninsula, Rio Negro, Cogolludo) were investigated. Several properties were analyzed by standard procedures. A detailed soil diagnostics and classification on "rañizos" were done, unlike those widely studied on "rañas" (similar landform), by identifying parallel pedogenetic processes in both formations. The genetic and geographic features of Alfisols, Ultisols and Inceptisols are closely related to the nature of their parent materials, based on quartzite and quartz conglomerates, sometimes with an arkosic matrix, red shale, polygenic gravels and pebbles. Soil features were determined by genuine soil-forming inherent lithological rock properties. Other driving factors were flat topography and enough soil formation time to allow intense pedogenesis. The main soil-forming processes were intense weathering, clay enrichment horizons with illuviation, red color caused by iron oxide dehydration and signs of pseudogleyzation processes. Such pedological formations can be considered endemisms; that is, "rare" soils and, up to a point, "relict". The soil reaction is acid/slightly acid with low base saturation. Despite lying on mountains, soils are characterized by moderate-low organic matter content. Soil conditions and climate provide good vine production requirements despite acidity levels. A common feature of all Rio Negro soils is the presence of gravel (size up to 3-5 cm), which is evenly distributed on arable layers. The results can be used to assess vineyard soil use in a potential Pago (Protected Denomination of Origin) and to extend the database of vineyard soils from poorly studied Mediterranean continental mountain regions.

Accumulation, distribution pattern and potential contamination of sulphur in vineyard soils of the Valdepeñas protected denomination origin

Soil is the basis for almost all global agriculture and the medium in which most terrestrial biological activity occurs. Viticulture represents an important agricultural practice in the Castilla-La Mancha (CLM) community. In this region, there are several protected denominations of origin (PDO), the largest being Valdepeñas. This paper describes the accumulation pattern of sulphur (S) in the vineyard soils of this PDO. Samples were collected from 90 vineyard soil profiles. Sulphur content was determined using an X-ray Fluorescence spectrometer in the solid mode on a powdered aliquot of each sample. The results indicated that the total S in soils varied from 0.54 to 6.90 (g·kg-1) in surface soil (0-30 cm) and from 0.39 to 2.80 (g·kg-1) on the subsurface layer (30-80 cm). When comparing the mean values of surface horizons to the subsurface horizons, S content lowered as soil depth increased. Kurtosis exceeded 45 % in all cases, which indicates a wide variability of concentrations. These findings can be explained by the continuous fertiliser and fungicide applications (and therefore S) in these production systems. Using the geoaccumulation index (Igeo), most soils were included in Class 0 (Igeo <0) and were, thus, S uncontaminated; only a few points can be considered pollutants. The obtained results should contribute to extend the scarce existing database on S in Mediterranean regions like that herein studied.

Mineralogical and Geochemical Nature of Calcareous Vineyard Soils from Alcubillas (La Mancha, Central Spain)

The mineralogical and geochemical patterns of calcareous vineyard soils located in Alcubillas (La Mancha, Central Spain) have been evaluated; also their variability has been studied. The information provided by this study supports the assessment of geochemical spatial variability, the origin of these soils, their elements and the factors that control their distribution. The presence of quartz, calcite, feldspar and, in particular, illite and kaolinite is due to their inheritance from surrounding lithologies (and pedological processes), which mostly include limestones, marls and other sedimentary rocks, as well as metasedimentary rocks of Hercynian origin. Furthermore, since the presence and accumulation of certain trace elements in vineyard soils is a relevant global hazard (in particular with respect to wine production quality), the spatial distributions of Ba, Cr, Cu, Pb, Rb, Sr, V and Zr (carried out using geostatistical techniques and geometry-based interpolation methods) were investigated in order to determine the origin of these trace elements. The presence of these elements can be interpreted as being due to geogenic, pedogenic and, in certain cases, anthropic influences. The nature of certain agricultural practices, including the use of fertilizers, phytosanitary products and machinery, could explain the local increases in some trace element contents.

Does mercury presence in soils promote their microbial activity? The Almadenejos case (Almadén mercury mining district, Spain)

Mercury is considered a very toxic element and important efforts are currently being made aimed at reduce or even eliminating its usage. Despite this trend, there are still sites where contamination by this metal is very marked, especially in the mining environment of Almadén where it has been exploited for thousands of years. The several forms in which Hg occurs in the soil interact differently with the organisms that live in/on it. The soil is a place where many biotic and abiotic variables act together. Through a detailed study of the edaphic characteristics of a decommissioned metallurgical enclosure, the presence of different chemical forms of Hg, the study of microbial activity (DHA) and, finally, parameters of the vegetation cover, such as specific distribution and biomass, we have tried to elucidate the effect of the presence of Hg in this precinct with a very high Hg pollution. The obtained results showed the affection patterns by which the different measured parameters vary, with special incidence to the microbial activity of the topsoil and to the specific distribution of the plants found in the studied area. The statistical multivariate analysis showed that significant correlations have been found between soil Hg fractions and between Hg fractions in plants; furthermore, soil conditions seem to be not related with Hg transfer from soils to plants. Biomass and DHA data indicate that the studied area is not affected by the presence of Hg species and lacks the expected toxic effects on the living organisms.

Environmental assessment of potential toxic trace element contents in the inundated floodplain area of Tablas de Daimiel wetland (Spain)

Contamination of aquatic systems with potentially toxic trace elements (PTEs) is a major problem throughout the world. The National Park Tablas de Daimiel (NPTD) is considered to make up one of the two most important wetlands in the Biosphere Reserve called "Wet Spot." Since PTEs are good indicator of the prevailing environmental conditions and possible contamination, soil samples collected from 43 sites were analyzed in order to investigate the levels and its distribution of these elements, in the inundated floodplain area of the NPTD wetland. In addition, some physicochemical parameters such as pH, electrical conductivity and organic matter were measured. The total concentrations of 32 trace elements were determined by X-ray fluorescence. The results show that there was accumulation of lead (Pb), tin (Sn), selenium (Se), antimony (Sb), copper (Cu), vanadium (V), nickel (Ni), zinc (Zn), arsenic (As), strontium (Sr) and zirconium (Zr)-in some cases at high concentrations. The interpolated maps showed that the distributions of some of these elements and in some cases the trend in spatial variability are pronounced and decrease from the inlet to the outlet. The values for some elements are higher than the reference values, which is consistent with contamination (some values are higher by a factor of more than 10 compared to the reference). In the case of iodine (I), the levels at some sample points are significantly more than ten times the reference; Se appears in the range from 1.0 to 9.8 mg/kg, with an average value of 3.1 mg/kg, and these can be considered as seleniferous soils. The concentrations found are consistent with the introduction in the wetland of pollution by human activities, such as agricultural non-point sources, uncontrolled fertilization over many years, treatment with urban wastewater and other possible sources.

Food safety objectives for Listeria monocytogenes in Spanish food sampled in cafeterias and restaurants

To gain more insight into the context of food safety management by public administrations, food safety objectives must be studied. The Valencian administration quantified the prevalence of Listeria monocytogenes in cafeterias and restaurants in this region of Spain between 2002 and 2010. The results obtained from this survey are presented here for 2,262 samples of fish, salad, egg, cold meat, and mayonnaise dishes. Microbiological criteria defined for L. monocytogenes were used to differentiate acceptable and unacceptable samples; more than 99.9% of the samples were acceptable. These findings indicate that established food safety objectives are achievable, consumer health at the time of consumption can be safeguarded, and food safety management systems such as hazard analysis critical control point plans or good manufacturing practices implemented in food establishments are effective. Monitoring of foods and food safety is an important task that must continue to reduce the current L. monocytogenes prevalence of 0.1% in restaurant or cafeteria dishes, which could adversely affect consumer health.