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.

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.

Red soil geochemistry in a semiarid Mediterranean environment and its suitability for vineyards.

A geochemical study of a red soil derived from plioquaternary materials was carried out. The soil was located in a region of complex geomorphology and pedologic evolution, with particular characteristics of a Mediterranean climate associated with processes of alteration, rubification, gleying (hydromorphism) and argillization. The depth distribution of 27 trace elements was studied in order to determine the amounts of these elements in the soil and its tendency. The mineralogy of the clay fraction was also studied along with other physico-chemical properties to elucidate in terms of attributes meaningful for viticulture. The geochemical composition of the horizons was studied. The effect of human activities on the soil was investigated as well as the geographical origin of Mancha wines. It was found that these activities did not give rise to significant variations of trace elements, although a discontinuity related to the accumulation of new materials was detected. Ultimately, using established productivity standards, suitability for the cultivation of vines on these soils was determined.

Application of FT-Raman spectroscopy to quality control in brick clays firing process.

This paper reports the study of the mineralogical evolution during the firing process (800-1150 degrees C) of the main types of raw materials used for the brick industry in Santa Cruz de Mudela (Ciudad Real, Spain). The mineralogical diversity observed in these materials leads to different behaviour during the shaping, drying and firing stages. Traditional use of similar working conditions in local industries, despite the mineralogical differences in the starting material, promotes the presence of defects in the drying and/or firing stages. This study attempt to implement some analytical guideline for the raw materials in order to improve the final product. Three types of raw materials obtained in different quarries have been characterised by means of chemical analysis with electron microprobe, powder X-ray diffraction and FT-Raman spectroscopy. The main difference between the clays studied is the carbonate content: one of the analysed samples is deficient in this component, while it is present as calcite (8%) or as calcite (14%) plus dolomite (10%) in the rest. The observed compositional differences seem to be relevant in the firing process. FT-Raman spectra reveal the onset of early vitrification (at about 900 degrees C) in the sample without carbonate. The importance of calcium and magnesium oxides, obtained from the corresponding carbonates, for the synthesis of new mineral phases that could slow down the vitrification process is discussed.

FT-Raman and powder XRD analysis of the Ba(SO(4))(x)(CrO(4))(1-x) solid solution.

The Ba(SO(4))(x)(CrO(4))(1-x) solid solution has been described in nature, forming the mineral Hashemite. From the geochemical point of view, however, anionic solid solutions have much interest because they are suitable systems to probe order-disorder phenomena. The solid solution analysed in the present study has, moreover, a special incentive in its possible use for the extraction from water, and immobilisation, of the pollutant Cr(VI) ion. The orthorhombic (space group Pnma) unit cell parameters of the solid solution change linearly with the mole fraction of both anions, decreasing with increase in the sulfate anion concentration. The vibrational spectroscopic study is centred on the behaviour of the anionic symmetric stretching band (nu(1),A(1)), whose characteristics are examined in detail. While the chromate anion band retains its wavenumber along the full compositional range, the sulfate anion band is shifted toward lower wavenumbers with decrease in the corresponding mole fraction. The positional disorder induced by the random anionic substitution results in strong increase of the halfwidth in both bands, which becomes greatest in the central member of the series.