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Very little information is available about Hg and Cr evolution in greenhouse soils. This paper presents the results of determining Hg and Cr in greenhouse soils in a semi-arid region in the southern Iberian Peninsula (Almeria, Spain), and assessing the enrichment level and the Potential Ecological Risk Index (PERI) according to crop age. Hakanson’s approach was used to evaluate the PERI. To investigate the behaviour of Hg and Cr in greenhouse soils over time, samples were grouped into values in soils for blocks according to crop age: 0 years, 5–10 years, 10–20 years, more than 20 years. The results showed that 74% of GS exceeded the obtained background level (37.1 μg kg−1) for Hg, with 43% (48.9 mg kg−1) for Cr. Temporal patterns indicated that these elements are accumulating in greenhouse soils and this trend was very significant for Hg. After more than 20 intensive crop-farming years, concentrations and the PERI had clearly increased. Although the ecological risk was moderate, our observations suggest that the farming practices performed in the last 35 years have allowed these metals to accumulate. In fact, the 15% of the studied soils presented a considerable potential risk and were the soils that had been used longer.

Tailings usually provide an unfavorable substrate for plant growth because of their multi-stress environment. Plants growing on naturally metal-enriched soils are of particular interest in this perspective, since they are genetically tolerant to high metal concentrations and have an excellent adaptation to extreme conditions. Soil and plant samples were taken in Peru, at a polymetallic mine (mainly Ag, Pb and Cu) in Cajamarca Province, Hualgayoc district. Top soils (0–20 cm) were analyzed for physical and chemical properties by standard methods. Total As, Cu, Pb and Zn concentrations in top soils were determined by ICP–OES. Similar metals in plants were analyzed separately (aerial and root system) by ICP–MS. Translocation Factor (TF) and Shoot Accumulation Factor (SAF) were determined to assess the tolerance strategies developed by these species and to evaluate their potential for phytoremediation purposes. The non-polluted soils had near neutral pH (6.8 ± 0.1), a great content of organic carbon (42 ± 4.0 g kg − 1 ) and a silt loamy texture. Soil and plant samples were taken at four locations (CA1, CA2, CA3, CA4) as well as the local reference topsoil (CA0). The range of total soil values in mg kg − 1 is as follows: As 280–1029; Cu 256–2070; Pb 3992–16,060 and Zn 11,550–28,059, respectively. Unusual elevated concentrations of Pb (over 1000 mg kg − 1 ) and TF greater than one were detected in shoots of six different plants species ( Ageratina sp., Achyrocline alata (Kunth) DC., Cortaderia hapalotricha Pilg., Epilobium denticulatum Ruiz & Pav., Taraxacum officinale Weber and Trifolium repens Walter ). Ageratina sp and E . denticulatum also showed elevated concentrations of Zn (over 10,000 mg kg − 1 ) and TF greater than one in some studied locations. However, the SAF was smaller than one. Controlled-environment studies must be performed to definitively confirm the Pb hyperaccumulation character of the cited plant species.

Pharmaceuticals (PhCs) are organic contaminants that have been detected in wastewater, surface water, and soils throughout the world. The presence of 10 commonly used PhCs in Spain (azithromycin, benzylpenicillin, citalopram, fluconazole, fluoxetine, ibuprofen, irbesartan, olanzapine, telmisartan, and venlafaxine) was analysed at four wastewater treatment plants, and the changes in their concentrations during treatment were assessed. Although certain some PhCs were degraded in the treated water, their presence in sewage sludge increased in all cases. The sewage sludge was composted using rice straw to degrade the PhCs, and the composting efficiency was modified by changes in the relative C/N ratio of the composting blend. Using a simple microbiological culture process for enrichment, 11 different strains of microorganisms that degraded specific PhCs were identified. Ibuprofen and azithromycin were metabolized by one and four strains, respectively, and both PhCs were used as a carbon source; in addition, six strains used irbesartan as a nitrogen source.

© The Author(s)., The main soil physical-chemical features, the concentrations of a set of pollutants, and the soil microbiota linked to penguin rookeries have been studied in 10 selected sites located at the South Shetland Islands and the Antarctic Peninsula (Maritime Antarctica). This study aims to test the hypothesis that biotransport by penguins increases the concentration of pollutants, especially heavy metals, in Antarctic soils, and alters its microbiota. Our results show that penguins do transport certain chemical elements and thus cause accumulation in land areas through their excreta. Overall, a higher penguin activity is associated with higher organic carbon content and with higher concentrations of certain pollutants in soils, especially cadmium, cooper and arsenic, as well as zinc and selenium. In contrast, in soils that are less affected by penguins' faecal depositions, the concentrations of elements of geochemical origin, such as iron and cobalt, increase their relative weighted contribution, whereas the above-mentioned pollutants maintain very low levels. The concentrations of pollutants are far higher in those penguin rookeries that are more exposed to ship traffic. In addition, the soil microbiota of penguin-influenced soils was studied by molecular methods. Heavily penguin-affected soils have a massive presence of enteric bacteria, whose relative dominance can be taken as an indicator of penguin influence. Faecal bacteria are present in addition to typical soil taxa, the former becoming dominant in the microbiota of penguin-affected soils, whereas typical soil bacteria, such as Actinomycetales, co-dominate the microbiota of less affected soils. Results indicate that the continuous supply by penguin faeces, and not the selectivity by increased pollutant concentrations is the main factor shaping the soil bacterial community. Overall, massive penguin influence results in increased concentrations of certain pollutants and in a strong change in taxa dominance in the soil bacterial community., This research was financed by the Spanish Ministry of Education and Science through projects CTM2010-11613-E to JB, CGL2005-06549-C02-02/ANT to AC, and TRA2009-0194 and AGL2011-29382 to RB, the last two co-financed by European FEDER funds. Support for travel costs was also obtained from grants CGL2007-29841-E and CTM2008-05205-E given by the Spanish Ministry of Science and Innovation to AC.

Cover crops may improve vineyard soil properties, grapevine nutrient status and berry composition, however, factors such as cover crop type, annual rainfall, climate and irrigation may change their effects on vineyards. From 2008 to 2011, the effects of a non-permanent cover crop and two pruning techniques on soil as well as vine nutrients and grapevine performance of two vineyards (cv. Tempranillo and cv. Bobal) were evaluated. For that purpose, two legumes were sown in inter-rows of hand-pruned vines in February and were tilled at flowering. Soil tillage, or cover cropping, was combined with either light pruning or severe pruning to study foliar nutrient variations. Soil N, P, K and total organic carbon (TOC) were determined in samples taken from the Ap1 horizon in January prior to vine pruning. Foliar N, P, K contents were measured in leaves sampled upon grape veraison. The differences between vineyards with cover cropping and bare soils suggest that legumes positively affected soil N (1.55 vs. 1.68 g kg−1 and 1.49 vs. 1.76 g kg−1 in Bobal and Tempranillo vineyards, respectively) and soil organic matter (SOM) (12.5 vs. 15.5 g kg−1 and 12.9 vs. 17.2 g kg−1 in Bobal and Tempranillo vineyards, respectively). The use of cover crops did not affect grapevine yields nor quality of Bobal and Tempranillo berry . Cover crops, or light pruning, did not alter the foliar N, P, K contents of both cultivars since their concentrations were similar to those found in the leaves from vineyards with soil tillage or severe pruning.

Heavy metal toxicity has become a global concern due to the ever-increasing contamination of soil, water and crops. Until recent decades little has been known about the remediation of mining sites using spontaneous plants in Latin America. Soil and plant samples were taken in Peru, at a polymetallic mine (mainly silver, lead and copper) in Cajamarca Province, Hualgayoc district. Top soils (0–20 cm) were analyzed for physical and chemical properties by standard methods. Total Pb and Zn concentrations in top soils were determined by ICP-OES. Similar metals in plants were analyzed separately (aerial and root system). Ti content was used as an indicator for contamination of plant samples with soil particles. Translocation Factor (TF) and Shoot Accumulation Factor (SAF) were determined to assess the tolerance strategies developed by these species and to evaluate their potential for phytoremediation purposes. The non polluted soils had near neutral pH (6.8 ± 0.1), a great content of organic carbon (42 ± 4.0 g kg − 1 ) and a silt loamy texture. According to the total metal concentrations, the polluted soils exceeded toxicity thresholds; large Pb (13,105 ± 3147 mg Pb kg − 1 ) and Zn (28,393 ± 3458 mg Zn kg − 1 ) concentrations were detected. Unusually elevated concentrations of these metals were detected in roots of Bidens triplinervia L. (e.g. up to 5180 mg Pb kg − 1 and 9900 mg Zn kg − 1 ) while Senecio sp. accumulated more heavy metals in shoots (e.g. up to 4250 mg Pb kg − 1 and 3870 mg Zn kg − 1 ). The TF values were B. triplinervia and > 1 in Senecio sp., while the SAF were B. triplinervia can be considered potentially useful for phytostabilization due to its capacity to restrict the accumulation of elevated amounts of Pb and Zn to the roots, while Senecio sp. could be utilized for phytoextraction technologies. Moreover, these plants showed an elevated transfer factor and grew in the presence of other toxic metals. The present study, to the best of our knowledge, is the first report on the metal accumulation in roots of B. triplinervia and provides a pioneer contribution to the very small volume of data available on the potential use of native plant species from contaminated sites in phytostabilization and phytoremediation technologies.

Metal mining gives access to very important resources but contributes to severe and diverse environmental problems. Until recently, little has been known about the remediation of mining sites in Latin America using metallophytes. The present study was designed to identify and characterize spontaneously growing heavy metal tolerant plant species in the area around the polymetallic Carolina mine in Hualgayoc (Cajamarca, Peru). The aim was to find species that are potentially useful for phytoremediation. Plants and soils were sampled and analysed for concentrations of As, Fe, Mn, Pb, Zn and Ti. The Translocation Factor (TF) and the Bioaccumulation Factor (BF) were determined and used to measure the amount of each element accumulated in shoots and roots of each plant species. The top soil had a neutral pH (7.4 ± 0.5), an organic carbon content of 24 ± 11 g kg− 1 and a loam texture. According to the total metal concentrations, all samples exceeded soil toxicity thresholds. Indeed, high Pb (from 120 to 111,290 mg kg− 1) and Zn (from 380 to 46,500 mg kg− 1) concentrations were detected in all soil samples. In plants, great Pb and Zn concentrations were found in the shoots of Plantago orbignyana Steinheil (from 6070 to 8240 mg Pb kg− 1 and from 8290 to 11,560 mg Zn kg− 1), Lepidium bipinnatifidum Desv. (from 6300 to 7240 mg Pb kg− 1 and from 4610 to 5370 mg Zn kg− 1), Baccharis latifolia Ruiz & Pav Pers. (from 2120 to 3060 mg Pb kg− 1 and from 1090 to 1490 mg Zn kg− 1), and Sonchus oleraceus L. (from 2180 to 2900 mg Pb kg− 1 and from 1340 to 1910 mg Zn kg− 1). The great TFs indicate that these plant species effectively translocate metals. L. bipinnatifidum shows the greatest TF values (i.e., 143 for Pb and 21.5 for Zn). These species could have potential for phytoextraction due to their large capacity to uptake and transfer elements, and their ability to grow in the presence of other toxic metals. To the best of our knowledge, the present study is the first report describing the metal accumulation ability of these plant species.

This study determines extractable levels of Cd, Cu, Pb, Zn, Ni and Co in western Almeria (Spain) greenhouse surface soil horizons using EDTA solution, which is identified as the fraction available for organisms and plants. It also establishes background levels, geochemical baseline concentration and reference values (RV), and investigates the possible relationships between soil properties and elemental concentrations. The results show that the soil concentration of these extractable heavy metals was high as those reported by other authors for Spanish agricultural soils. The available RV concentrations obtained (mg kg −1 ) were: Cd 0.17, Cu 1.6, Pb 13.8, Zn 5.0 Ni 1.7 and Co 2.9. Using the upper baseline criterion, 95% of greenhouse soils present a relatively higher content of extractable heavy metals given their Cd and Cu concentration. Significant correlations between total and EDTA-extractable metal levels were found for Zn, Pb, Cu, Cd and Ni. Soil properties also related to heavy metals content, suggesting that Cd, Cu, Pb and Zn are of similar origin and relate to anthropic activities, and implies the same interactions and/or relationships among these metals.

The study of metal contents in industrial, agricultural or/and polluted soils compared with natural or unpolluted soils is currently necessary to obtain reference values and to assess soil contamination. Nonetheless, very few works published appear in international journals on elements like Se, Li and Sr in Spanish soils. This study determines the total levels of Se, Li, Sr, As, Cd, Co, Cr, Cu, Ni, Pb, V, Zn, Fe, Mn and Ba in 14 natural (unpolluted) soils (Gypsisols, Leptosols, Arenosols and Acrisols), 14 agricultural soils (Anthrosols, Fluvisols and Luvisols), and 4 industrial–urban affected-surface soil horizons (Anthrosols and Fluvisols) of Eastern Spain. The geochemical baseline concentrations (GBC) and reference values (RV) have been established, and the relationships among elements and also between soil properties and elemental concentrations have been analysed. The RV obtained in this study were (mg kg −1 ): Se 2.68, Li 115, Sr 298, Cd 0.97, Co 35, Cr 217, Cu 46, Ni 50, Pb 137, V 120, Zn 246, Fe 124,472, Mn 2691, and Ba 743. The RV for Se and Li were used as a preliminary approach to assess soil contamination in Spanish soils. The results confirm human impact on Sr, As, Cd, Cr, Cu, Ni, Pb and Zn soil concentrations, but evidence no deviation from natural Se, Li, Co, V, Fe, Mn and Ba concentrations. The results obtained from the statistical analysis reveal significant correlations between some elements and clay and soil organic matter (SOM) contents, indicating that metal concentrations are controlled by soil composition. One particularly interesting finding is the high correlation coefficients obtained between SOM and Se, Cd, Cr, V, Fe, and Mn, and between clay and Cd, Zn, V, Fe and Mn. Once again, these facts confirm the role of SOM and clay minerals in soil functions and that soil is an ecosystem element responsible for maintaining environmental quality.

Thermal infrared (TIR) emissivities of soils with different textures were measured for several soil moisture (SM) contents under controlled conditions using the Box method and a high-precision multichannel TIR radiometer. The results showed a common increase of emissivity with SM at water contents lower than the field capacity. However, this dependence is negligible for higher water contents. The highest emissivity variations were observed in sandy soils, particularly in the 8-9-μm range due to water adhering to soil grains and decreasing the reflectance in the 8-9-μm quartz doublet region. Thus, in order to model the emissivity dependence on soil water content, different approaches were studied according to the a priori soil information. Soil-specific relationships were provided for each soil texture and different spectral bands between 8 and 13 μm, with determination coefficients up to 0.99, and standard estimation errors in emissivity lower than ± 0.014. When considering a general relationship for all soil types, standard estimation errors up to ±0.03 were obtained. However, if other soil properties (i.e., organic matter, quartz, and carbonate contents) were considered, along with soil water content, the general relationship predicted TIR emissivities with a standard estimation error of less than ±0.008. Furthermore, the study showed the possibility of retrieving SM from TIR emissivities with a standard estimation error of about ±0.08 m3 . m-3.

p.- 4 Tabls.- 6 Figs., Soil organic carbon stock (SOCS) assessments at a national level are essential in the climate change mitigation role. Our study provides the first assessment of the SOC stored in entire Spanish surface soils obtained from one sampling protocol within a regular sampling framework in a short edaphic time. In this study, we analysed topsoil samples (0–30 cm) from 4401 locations. SOC, soil bulk density and stoniness were measured to estimate SOCS. The results showed that half the Spanish areas obtained a SOC value below 1%. There is inherently wide spatial variability in SOC contents in Spain with low SOC concentration levels located in southern areas. The lowest SOC levels were associated with agricultural soils. However, no statistically significant differences were found between forestlands and grasslands. The mean SOCS in the Spanish topsoil layer was 56.57 Mg C ha− 1 and the total stored in topsoil was 2.8 Pg C. We were surprised to find that our estimates were 40% lower than those known to date for Spain. The results herein highlight the potential land use change for SOC sequestration in Spanish soils. Certain changes in agricultural practises (conservation tillage) or converting some unproductive croplands into grasslands or forestlands can increase carbon sequestration in soils., We gratefully acknowledge the funding provided by the Spanish Ministry of the Environment and Agricultural through several projects (CC01-0013, CC05-004, AEG05-029, CC00-0026) for some years. We also wish to thank the Spanish Ministry of Science and Innovation for Project CGL2013-43675-P.

In the present study, we have investigated relationships among several soil parameters (pH, organic matter, total carbonate, macronutrients, electrical conductivity, cation-exchange capacity) and macronutrient and cardenolide contents in leaves of wild Digitalis obscura plants. Young and mature leaves and soil samples were collected in ten different areas, corresponding to three Mediterranean bioclimatic belts (thermo-, meso-, and supramediterranean belts). Soil and leaf macronutrient (N, P, K, Ca, and Mg) contents and leaf cardenolide contents were determined. Bioclimatic conditions influenced the development of D. obscura, biomass being lowest in plant populations of the supramediterranean belt, but they did not exert any relevant effect on the contents of macronutrients in soils and plants. Magnesium (total and EDTA-extracted) was the only soil macronutrient significantly correlated with its content in the plant. Cardenolide contents were negatively correlated with the N, P, and K contents in young leaves, whereas such correlations were highly significant and positive for Mg.

This study determines total levels of three (Cd, Pb and Ni) potentially toxic trace elements in western Almería (Spain) greenhouse surface soil horizons using microwave digestion; it establishes the geochemical baseline concentration, and it investigates possible relationships between soil properties and elemental concentrations. The results show that the soil concentration of these heavy metals is lower than mentioned in the European and Spanish normative, but they are higher than those reported by other authors working on agricultural soils. The obtained geochemical baseline concentrations (mg kg(-1)) were: Cd 0.4-0.8, Pb 2.5-89.9 and Ni 16.1-30.7. Using the upper baseline criterion, 88% of greenhouse soils have relatively higher content of heavy metals because of their Cd, Pb and Ni concentration. Moreover, soil properties are related to heavy metals contents suggesting that among Cd, Pb and Ni have a similar origin and those total metal concentrations are controlled primarily by soil compositions.

Mature leaves of wild-growing Digitalis obscura plants and soil samples were collected in four different regions. Soil and leaf mineral nutrient contents as well as biomass and cardenolide productions were determined. The soils in the four collection sites, basic and highly calcareous, showed significant interpopulation differences in phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), manganese (Mn), copper (Cu), and zinc (Zn). Foliar mineral nutrients and cardenolides also varied among populations. Highest cardenolide yield was found in those Digitalis populations presenting a better development. The cardenolide content exhibited significant negative correlations with the levels of P in plants and those of Cu in soils, suggesting that these elements may affect cardenolide biosynthesis.

The total, water soluble and extractable concentrations with EDTA of As from topsoils from the Ambles Valley (Avila, Spain) were determined. The geochemical baseline concentrations of total As were established, and the relationships between the concentration of the different As forms and soil properties were investigated. Total As content in soils was related with parent material, whereas anthropogenic activities affected its mobility. Iron, aluminium, clay content, soil organic matter and soil pH were the main controlling factors for As soil concentrations. The geochemical baseline concentrations obtained (mg kg − 1 ) were 7.3–35 in soils on granite parent material and 2.2–6.8 in soils on alluvium–colluvium parent material for total As. The baseline concentration values for the water soluble and EDTA extractable As forms were also established. For water soluble As, the baseline concentrations (mg kg − 1 ) were 0.06 for natural soils and 0.37 for agricultural and industrial soils, respectively, and the baseline concentrations for As extractable with EDTA were 0.39 mg kg − 1 .

This study characterises and compares Cr, Ni, Pb, Cu, Zn and Cd (HMs) contents and the main edaphic parameters in arable soils (AS) from western areas of the Andalusian Autonomous Community (SE Spain) with greenhouse soils (GS) from the province of Almería, one of the most productive agricultural systems in Europe. We explored 199 GS and 142 AS, representing local and regional scales of variation in this important Mediterranean area. The hazardousness of HMs was particularly relevant in GS where agricultural practices, which centre on maximising production, end up with products that finally enter the human food chain directly. Despite their similar edaphic characteristics, the main differences between AS and GS were nutrients and HM contents such as P, K, Cd, Pb and Zn, suggesting the widespread use of agrochemicals in greenhouse farming. Cd concentration in GS tripled that in AS. Here, we conclude that despite anthropogenic HM input, the association patterns of these elements were similar on the two spatial variability scales. Cd, Pb and Zn contents, and partly those of Cu, were related with agricultural practices. On the short spatial scale, grouping these HMs gave very high contents in GS. The associations found with Cr and Ni suggest a lithogenic influence combined with a paedogenic effect on spatial maps; this natural origin input becomes more marked on the long spatial scale represented by AS, where the main Cr and Ni contents were found in the vicinity of Mountain areas not influenced by human activities. © 2013 Elsevier B.V.

The behaviour and disappearance of Diazinon and Prometryn from orchard soils were monitored in a typical orchard plot in Valencia (Spain). Soil samples were collected at two different depth ranges (0–5 cm, and 5–30 cm below the soil surface) at each of five sites within the plot. The samples were taken from several horizons in order to determine whether or not there was any leaching of the pesticide. Since soil heterogeneity can affect pesticide behaviour in terms of adsorption, transport and persistence, soil characterization is necessary; hence, tests for determining sand, silt and clay content were also carried out. A simple, rapid and effective method was used for extracting and enriching pesticides, based on the use of 47-mm disks with octyl bonded silica sorbent. The adsorbed pesticides were eluted with ethyl acetate prior to capillary gas chromatography.

The movement and degradation of the herbicide thiobencarb was monitored in a rice field near Lake Albufera (Valencia, Spain). This area constitutes an ecological unit of great environmental interest. Soil samples were collected from the surface and the subsurface of the rice field treated with this herbicide. Soil characterization tests for pH, organic matter, moisture and texture were also carried out. At the same time, samples of water were taken from the inundated plot 10 cm below the surface. Both types of sample were extracted by solid-phase extraction using 47-mm discs of octyl-bonded silica sorbent and eluted with ethyl acetate, with average recoveries for this compound of 63 and 93% from soil and water, respectively. The analyses were carried out by gas chromatography with nitrogen-phosphorus detection. Sample components were separated with a 30 m × 0.25 mm I.D. fused-silica capillary column coated with 50% phenylmethyisilicone (DB-17).

13 páginas, 3 figuras, 4 tablas, 1 foto., The aim of the research was to relate the spectral response of rice to heavy metal concentration in soil of Albufera Natural Park. The spectral observations were values of the crop reflectance obtained from the Landsat-5 Thematic Mapper NIR and Red bands expressed by the Normalized Difference Vegetation Index, NDVI. Soil samples of the surface 20 cm were analyzed for total and extractable heavy metal content. The strongest correlations between NDVI and heavy metal in soil were found between the available fractions of Ni, Pb, Cd, Cu and Zn and the toxicity index, Zn equivalent, defined by Zn Eq = (1xZn)+(2xCu)+(8xNi) where metal concentrations are in mg per kg of soil.

Heavy metals have become one of the most serious anthropogenic stressors for plants and other living organisms. Having efficient and feasible bioassays available to assess the ecotoxicological risks deriving from soil pollution is necessary. This work determines pollution by Cd, Co, Cr, Cu, Ni, Pb, V and Zn in two soils used for growing rice from the Albufera Natural Park in Valencia (Spain). Both were submitted to a different degree of anthropic activity, and their ecotoxicological risk was assessed by four ecotoxicity tests to compare their effectiveness: Microtox test, Zucconi test, pot bioassay (PB) and soil plate bioassay (SPB). The sensitivity of three plant species (barley, cress and lettuce) was also assessed. The results reveal a different degree of effectiveness and level of inhibition in the target organisms' growth depending on the test applied, to such an extent that the one-way analysis of variance showed significant differences only for the plate bioassay results, with considerable inhibition of root and shoot elongation in seedlings. Of the three plant species selected, lettuce was the most sensitive species to toxic effects, followed by cress and barley. Finally, the results also indicate that the SPB is an efficient, simple and economic alternative to other ecotoxicological assays to assess toxicity risks deriving from soil pollution.

The relationship between cobalt, copper and zinc content of soils and the vegetables grown in them is discussed. Samples of soil and edible vegetables were taken from 15 different sites, corresponding to four agricultural areas exposed to different degrees of environmental pollution: high industrial and traffic, high industrial and urban, and low industrial and urban pollution. Elements were determined by atomic absorption spectroscopy. Variance analysis (ANOVA) was applied to cobalt, copper and zinc content of vegetables and soils in order to detect significant differences among soils of different areas and the vegetables grown there. The possible relationship between the heavy metal content of soils (total and extractable) and of the vegetables grown in them was estimated by the correlation coefficient value. Statistically significant correlations were observed between the total and extractable cobalt content of soils and of roots and bulbs (p < 0.1) and between the total copper content of soils and of inflorescences (p < 0.05). In the case of zinc no correlation was found. Beziehung zwischen dem Gehalt an Kobalt, Kupfer und Zink in Bodenproben und Gemusen Es werden die Beziehungen zwischen dem Gehalt an Kobalt, Kupfer und Zink in Bodenproben und darin gewachsenen Gemusen diskutiert. Boden- und Gemuseproben werden an 15 verschiedenen Stellen aus 4 landwirtschaftlichen Arealen entnommen, die in unterschiedlichem Umfang Umweltverunreinigungen ausgesetzt sind: Hohe Industrie- und Verkehrsverunreinigungen, hohe Industrie- und Stadtverunreinigungen sowie geringe Industrie- und Stadtverunreinigungen. Die Elemente werden durch Atomabsorptions-Spektroskopie bestimmt. Zur Ermittlung signifikanter Unterschiede zwischen Bodenproben verschiedener Areale und den darauf gewachsenen Gemusen werden Varianzanalysen (ANOVA) zum Gehalt an Kobalt, Kupfer und Zink beider Probenarten vorgenommen. Mogliche Beziehungen zwischen dem Schwermetallgehalt der Bodenproben (gesamt und extrahierbar) und den darin gewachsenen Gemusen werden mittels des Korrelationskoeffizienten bestimmt. Statistisch signifikante Korrelationen werden zwischen Gesamt- und extrahierbarem Kobaltgehalt von Bodenproben und von Wurzeln und Knollen (p < 0,1) sowie zwischen dem Gesamtkupfergehalt von Bodenproben und von Blutenstanden (p < 0,05) ermittelt. Im Fall von Zink werden keine Korrelationen festgestellt.

This paper provides the first available information on the determination of the total mercury content in different Mediterranean calcareous soils by thermal decomposition, amalgamation and atomic absorption spectrophotometry. Fifty-three samples from five soil use groups (natural, dry land, greenhouse, irrigated and rice farming soils) were analysed. The results show that the levels of mercury in these soils were 9.4–1585 μg kg −1 . Soil organic matter and the zinc equivalent index have been related to Hg content in soils, suggesting that Cu, Ni, Zn and Hg are of a similar origin. The background level (BL), geochemical baseline concentrations (GBC) and the reference value (RV) were established from natural soils. Calculations are according to the log-normal distribution criterion. The BL, GBC and RV values obtained were 25.1, 9.8–64.3, and 64.3 μg kg −1 , respectively. The BL was similar to the baseline concentration in soils obtained at Admiralty Bay (Antarctica) (24.6 μg kg −1 ) and a Spanish peat bog (Galicia) (22 μg kg −1 ). These data show that rice farming soils ( gleyic – calcaric Fluvisols, Fluvaquents ), irrigated soils ( calcaric Fluvisols, Xerofluvents ) and some greenhouse soils ( cumulic Antrosols ) presented much higher levels, indicating contamination. Hg accumulation in these soils was associated with local anthropogenic sources.

The cadmium, lead and nickel content of soils of four agricultural areas exposed to different degrees of environmental pollution and vegetables grown there were measured by Atomic Absorption Spectrophotometry (AAS). In order to ascertain the possible relationship between the heavy metal content of soils (total and extractable) and of vegetables grown in them, the correlation between the two was calculated. The highest correlation values between metal content of soil and vegetables are these corresponding to nickel: the total metal content in soils and leaves-stems are linear (p

[1] The influence of soil water content in thermal infrared emissivity is a known fact but has been poorly studied in the past. A laboratory study for quantifying the dependence of emissivity on soil moisture was carried out. Six samples of surface horizons of different soil types were selected for the experiment. The gravimetric method was chosen for determining the soil moisture, whereas the emissivity was measured at different soil water contents using the two-lid variant of the box method. As a result, the study showed that emissivity increases from 1.7% to 16% when water content becomes higher, especially in sandy soils in the 8.2–9.2 μm range. Accordingly, a set of equations was derived to obtain emissivity from soil moisture at different spectral bands for the analyzed mineral soils. Moreover, results showed that the spectral ratio decreases with increasing soil water content. Finally, the study showed that systematic errors from 0.1 to 2 K can be caused by soil moisture influence on emissivity.

The sequential extraction procedures described by Tessier et al., McGrath and Cegarra, and Gimeno-García et al. were compared to investigate trace element (As, Cr, Cu, Pb, and Zn) partitioning patterns and extraction efficiency in three contaminated soils from Mediterranean regions of Spain. Soils were selected from Onda (Castellón) (S1), Aznalcóllar (Sevilla) (S2), and Silla (Valencia) (S3). S1 was a soil contaminated with Pb and Zn after dumping of wastes from the manufacture of ceramic tiles, S2 was polluted accidentally with a highly acid and As-concentrated sludge from mining activities, and S3 was a soil with a high Cr content from tannery sludge disposal. Trace element distribution in the soils--soluble, exchangeable, organically bound, precipitated with carbonates, bound to iron and manganese oxides, and precipitated with sulfides fractions--varied significantly according to the extraction procedure used. In addition, different extraction efficiencies were found for the three sequential extraction procedures compared. Finally, the trace elements studied showed different and specific distribution patterns between the various soil fractions examined.

It is known that the sources of soil contamination can be endogenous or exogenous and that exogenous contamination may be direct or indirect. In this work, an environmental pesticide fate study was conducted in soil profiles collected from 23 rice field sites in an important Mediterranean wetland (Albufera Natural Park, Valencia, Spain) from April 1996 to November 1997. Temporal and spatial distribution of 44 pesticide residues in an alluvial Mediterranean soil (gleyic-calcaric Fluvisol, Fluvaquent) were monitored. During this period, the levels of pesticide residues in different soil horizons (Ap1 0–12 cm, Ap2 12–30 cm, ApCg 30–50 cm, C1gr 50–76 cm, and C2r 76–100 cm) were investigated. In addition, information was collected on agricultural pesticide application practices and soil characteristics. Distribution throughout the soil profile showed that pesticide concentrations were always higher in the topsoil (Ap1 horizon), in the autumn season, and in the border with citrus-vegetable orchard soils (calcaric Fluvisol, Xerofluvent). Chlorpyrifos (organophosphorus), endosulfan (organochlorine), and pyridaphenthion (organophosphorus) insecticides were, respectively, the most detected of all the pesticides investigated. These results were associated with processes, such as nonleaching, transport by movement into surface waters, retention, volatilization, and chemical and biological degradation in the topsoil, as well as with direct and indirect exogenous contamination sources.

An environmental fate study was conducted in a citrus orchard plot in Valencia (Spain) in the fall of 1993. Dissipation and distribution of atrazine, simazine, chlorpyrifos and tetradifon residues following their controlled addition for agricultural purposes in a mediterranean red soil (Luvic Calcisol, Rhodoxeralf) were evaluated. During a two-month period, the amounts of applied pesticides in different soil layers (0-0.05, 0.05-0.22, 0.22-0.42, and 0.42-0.52 m) were monitored. In addition, information on soils, weather and agricultural practice were collected. Degradation half-lives were calculated, assuming zero-order kinetics: 11 days for atrazine, 12 days for simazine, 10 days for chlorpyrifos, and 18 for tetradifon. The distribution through the soil profile shows that the pesticide concentrations were always highest in the upper layer (0-0.05 m) of soil, and that atrazine was the most mobile of all the four pesticides investigated.

The presence of Cd, Co, Cu, Ni, Pb, Zn, Fe and Mn in different inorganic fertilizers (urea, calcium superphosphate, iron sulphate and copper sulphate) are evaluated and the contribution of these metals to the soils in this way is estimated. The studied zone corresponds to rice farming and is at the north of Albufera Natural Park (Valencia, Spain). The results obtained show that Superphosphate is the fertilizer that contains the highest levels of Cd, Co, Cu and Zn as impurities. Copper sulphate and iron sulphate have the most significant contents of Pb, and are the only fertilizers in which Ni is detected. The most significant additions of impurities that the soil received by agricultural practices were of the heavy metals Mn, Zn, Co and Pb. Two contamination indexes have been applied to provide a basis for comparison for heavy metal potential toxicity. These results denote no potential toxicity for heavy metals in the studied soils.

7 páginas, 7 tablas. ScienceDirect, The concentrations of Cd, Co, Cu, Ni, Pb, Zn, Fe and Mn in different inorganic fertilizers (urea, calcium superphosphate, iron sulphate and copper sulphate) and in pesticides (two herbicides and one fungicide) are evaluated together with the contribution of these metals in soils from their use. The study was mane in rice farming areas to the north of Albufera Natural Park (Valencia, Spain). The results obtained show that superphosphate is the fertilizer that contains the highest concentrations of Cd, Co, Cu and Zn as impurities. Copper sulphate and iron sulphate have the most significant concentrations of Pb, and are the only fertilizers in which Ni was detected. The three pesticides analysed show similar Cd contents and the highest levels of Fe, Mn, Zn, Pb and Ni are found in the herbicides. The most significant additions of heavy metals as impurities that soil receives from agricultural practices, are Mn, Zn, Co and Pb. Three contamination indexes have been applied to provide a basis for comparison of potential heavy metal toxicity. These results denote the potential toxicity of heavy metals in the studied soils.

8 páginas, 1 figura, 4 tablas., The distribution of Cd, Co, Cu, Ni, Pb, Zn, Mn, and Fe in soils dedicated to rice crops have been studied. Total content and extractable fraction have been determined by acid digestion and extraction with EDTA, respectively. A method of selective sequential extraction (SSE) has been applied to determine the fraction of the metals bound to organic matter, soluble plus exchangeable, precipitated with carbonates, associated to Fe and Mn amorphous oxides, precipitated with sulfides, and the residual; all the elements show their most important fraction as precipitates, mainly as forms of sulfides and carbonates. The forms available by plants and bound to the organic matter are less represented, except for Cu and Ni., The authors thank the C.I.C.Y.T. NAT91-1129 project for financial support.