Características del suelo y vegetación de un área salina limítrofe de la marisma del Guadalquivir (Isla Menor)

Han sido estudiadas dos zonas salinas limítrofes de la marisma del Guadalquivir. Sus suelos fueron clasificados como: Vertic (?) Aquic Xerofluvents y Aquic Vertic Xerofluvents respectivamente. Se ha podido comprobar que el perfil salino potencial corregido de la zona número 2, uniforme texturalmente, es una síntesis adecuada de los perfiles salino y agronómico, circunstancia no extensible a la zona núm. 1, donde la notable heterogeneidad textural hace que las conductividades eléctricas de los extractos suelo-agua = 1/5 Y de saturación no sean comparables. La zona número 1 posee vegetación esencialmente halófita, mientras que en la zona número 2 es glicófita fruto de su considerable reducción superficial de salinidad tras períodos de lluvia. Sin embargo, la salinidad media global del perfil número 2 es superior a Ia del perfil número 1. En ambas zonas predomina una salinidad tipo cloruro, aunque también se debe hacer referencia a una salinidad magnésico-sódica. Se observa que ciertas plantas halófitas acumuladoras de sales, de contenidos sódicos muy superiores a los de potasio, presentan contenidos magnésicos sensiblemente superiores o los de calcio. Otras especies tolerantes a la salinidad, cuyo nivel de sodio es inferior al de potasio, presentan contenidos de magnesio semejantes o inferiores los de calcio.Two areas at the border of the marsh of Guadalquivir river have been studied.The soils are Vertic (?) Aquic Xerofluvents (area 110.1) and Aquic Vertic Xerofluvents (area no. 2). If the texture is uniform, the potential saline profile is a very good approximation of both saline and agronomic profiles. Area no. 2 is populated by glycophytes because oí the decrease of surface salinity after rainy periods, since its bulk salinity is higher than the corresponding to area no. 1. which is populated by halophytes. Salinity in both areas is of chloride type, although it should be mentioned the presence of magnesium besides sodium ions. This circumstance seems to affect the vegetation

Soil and vegetation of two saline areas of the 'Lebrija' marsh (Seville). II. Plant Characteristics

Se han identificado las especies vegetales de dos zonas salinas de la Marisma de Lebrija (Sevilla). La reducción superficial de salinidad durante períodos de lluvia permite la presencia de muchas especies de carácter glicofítico. El material vegetal analizado suele poseer notables contenidos de nitrógeno, aunque su disponibilidad, como la de fósforo, puede reducirse considerablemente ante fuertes niveles salinos. Las especies que acumulan sodio presentan contenidos de magnesio superiores a los de calcio, ocurriendo lo contrario en las que excluyen sodio. Exceptuando algunas halófitas que poseen bajos contenidos de Mn, las restantes especies examinadas satisfacen sus necesidades de Fe, Mn, Zn y Cu. El material vegetal analizado no presenta excesivos niveles de boro a pesar de su significativa presencia en el suelo. Algunas de las especies analizadas alcanzan contenidos apreciables de grasa y reducidos porcentajes de cenizas. El conjunto de datos obtenidos indica que muchas de las especies de la Marisma del Guadalquivir presentan un valor nutritivo que las hace potencialmente útiles en el campo de la pascicultura.Naturally occurring plant species of two saline areas from Lebrija Marsh have been listed. It has been checked that the decrease in surface salinity during rainy veriods enables the presence of many glycophyte species. Plant material analysed generally shows noticeable nitro gen contents. However nitrogen and possibly phosphorus availability may be reduced for high salt levels. Species which accumulate sodium have higher levels of magnesium than calcium. On the contrary, species whose salinity tolerance is based upon ion exclusion mechanismes show an opposite behaviour. Analyses made of a number of native plants reveale that their requirements of micronutrients Fe, Mn, Zn and Cu are satisfied. Only some halophytes have comparative1y low Mn contents. Plant material examined does not exhibit excessive levels of B despite its noticeable presence in the soil. Medicago polymorpha L., Trifolium resupinatum L. and Phalaris paradoxa L. have an important level of fat and not very significant ash contents. Data reported here indicate that numerous species from Guadalquivir River Marsh have a considerable nutritive value

Soil and vegetation of two saline areas of the "Lebrija" marsh (Seville). II. Plant characteristics

20 páginas, 8 tablas, 48 referencias.[ES]: Se han identificado las especies vegetales de dos zonas salinas de la Marisma de Lebrija (Sevilla). La reducción superficial de salinidad durante períodos de lluvia permite la presencia de muchas especies de carácter glicofítico. El material vegetal analizado suele poseer notables contenidos de nitrógeno, aunque su disponibilidad, como la de fósforo, puede reducirse considerablemente ante fuertes niveles salinos. Las especies que acumulan sodio presentan contenidos de magnesio superiores a los de calcio, ocurriendo lo contrario en las que excluyen sodio. Exceptuando algunas halófitas que poseen bajos contenidos de Mn, las restantes especies examinadas satisfacen sus necesidades de Fe, Mn, Zn y Cu. El material vegetal analizado no presenta excesivos niveles de boro a pesar de su significativa presencia en el suelo. Algunas de las especies analizadas alcanzan contenidos apreciables de grasa y reducidos porcentajes de cenizas. El conjunto de datos obtenidos indica que muchas de las especies de la Marisma del Guadalquivir presentan un valor nutritivo que las hace potencialmente útiles en el campo de la pascicultura.[EN]: Naturally occurring plant species of two saline areas from Lebrija Marsh have been listed. It has been checked that the decrease in surface salinity during rainy veriods enables the presence of many glycophyte species. Plant material analysed generally shows noticeable nitro gen contents. However nitrogen and possibly phosphorus availability may be reduced for high salt levels. Species which accumulate sodium have higher levels of magnesium than calcium. On the contrary, species whose salinity tolerance is based upon ion exclusion mechanismes show an opposite behaviour. Analyses made of a number of native plants reveale that their requirements of micronutrients Fe, Mn, Zn and Cu are satisfied. Only some halophytes have comparative1y low Mn contents. Plant material examined does not exhibit excessive levels of B despite its noticeable presence in the soil. Medicago polymorpha L., Trifolium resupinatum L. and Phalaris paradoxa L. have an important level of fat and not very significant ash contents. Data reported here indicate that numerous species from Guadalquivir River Marsh have a considerable nutritive value.Peer reviewe

La moltiplicazione del melo con la tecnica della micropropagazione. Variazione del pH in substrati diversi durante la fase di moltiplicazione

10 páginas, 2 figuras, 5 tablas, 9 referencias.-- Esta revista es continuación de Rivista della Societa Toscana di Orticoltura y continuada por Advances in horticultural science.I numerosi studi condotti in questi ultimi 20 anni sulla applicazione della coltura in vitro a diverse specie coltivate, hanno focalizzato principalmente la messa a punto dei terreni nutritivi, il ruolo dei fitoregolatori nelle diverse fasi di crescita ed il controllo ormonale sulla morfogenesi. Quasi del tutto trascurata, come appare dai lavori riportati in bibliografia, sono state invece le indagini su altri fattori che probabilmente esercitano un ruolo di primo piano sulla crescita e sui processi morfogenetici che avvengono in vitro.Peer reviewe

Evaluation of pastures for horses grazing on soils polluted by trace elements

12 pages,3 figures, 9 tables, 46 references.-- Adjuntamos página de errata.Pasture established on polluted soil may pose a risk to grazing livestock creating a requirement for mechanical management which may affect biodiversity and expend energy. The risk associated with managing pasture by grazing horses (non-edible livestock) is being assessed in the Guadiamar Valley (SW Spain), where soils are polluted with trace elements following a major pollution incident. Soil pollution does not affect biomass production or floristic composition of pasture, although both variables influence trace element accumulation in herbage. Element concentrations in herbage are below maximum tolerable limits for horses. Faecal analysis showed regulated absorption of essential elements, while non-essential elements seemed preferentially excreted. Elemental content of horse hair did not differ in animals from polluted and control pastures. If pastures are managed by grazing, periodic monitoring is recommended in view of the long-term chronic trace element exposure in these systems. 2008 Springer Science+Business Media, LLC.We acknowledge the Regional Ministry of Environment (Junta de Andalucía) for supporting this study and the Spanish Ministry of Education for a PFU grant awarded to M.T. Domínguez. Dr. P Madejón thanks her Ramón y Cajal contract financed by the Spanish Ministry of Innovation and Science.Peer reviewe

Effect of succesive applications of urban compost on soil potassium availability

10 páginas, 1 figura, 6 tablas, 22 referencias.[EN]: The effect of successive applications of urban compost (up to 150 and 400 t ha-1 in six applications over eight years) on the status of K in a calcareous soil was tested in a greenhouse experiment. An 8-15-15 complex fertilizer was also applied for comparison. Five years of ryegrass and three of horticultural plants (tomato and eggplant) were successively cropped during the experiment. Increases of soluble- and available-K were observed with both organic and inorganic fertilization, although statistical differences between treatments were not significant. On the contrary, total-K does not increase when compost is added. Values of total-K when compost is added at maximum rate tend to be even lower than those in the control, which could be related with the observed lowering of tite soil's bulk density. Highest plant K-uptake corresponds to the application of the maximum compost dosage, and is much higher than the amount of K applied with compost.[ES]: Se estudia a nivel de invernadero el efecto de aplicaciones sucesivas de compost urbano (hasta 150 y 400 t ha-1 en seis aplicaciones, a lo largo de ocho años) sobre niveles de K de un suelo calcáreo. A efectos comparativos se utilizó un abono inorgánico complejo, 8-15-15. Durante los cinco primeros años se cultivó ryegrass y plantas hortícolas (tomate y berenjena) durante los tres años restantes. La fertilización orgánica e inorgánica incrementó los niveles de K soluble y disponible en el suelo, aunque sin diferencias estadísticamente significativas entre tratamientos. Los niveles de K total no se incrementaron como consecuencia de la adición de compost. Resultaron incluso algo más bajos que en el control cuando se aplicó la dosis más alta de compost, lo que podría estar relacionado con la reducción de densidad aparente que ocasiona este tratamiento en el substrato. La máxima absorción vegetal de K correspondió al tratamiento con dosis mayor de compost, siendo la cantidad absorbida superior a la aportada por el compost.Peer reviewe

Facilitating the afforestation of Mediterranean polluted soils by nurse shrubs

11 páginas.-- 5 figuras.-- 2 tablas.-- Supplementary data related to this article can be found at http://dx.doi.org/10.1016/j.jenvman.2015.07.009.The revegetation of polluted sites and abandoned agricultural soils is critical to reduce soil losses and to control the spread of soil pollution in the Mediterranean region, which is currently exposed to the greatest soil erosion risk in Europe. However, events of massive plant mortality usually occur during the first years after planting, mainly due to the adverse conditions of high irradiance and drought stress. Here, we evaluated the usefulness of considering the positive plant–plant interactions (facilitation effect) in the afforestation of polluted agricultural sites, using pre-existing shrubs as nurse plants. We used nurse shrubs as planting microsites for acorns of Quercus ilex (Holm oak) along a gradient of soil pollution in southwestern Spain, and monitored seedling growth, survival, and chemical composition during three consecutive years. Seedling survival greatly increased (from 20% to more than 50%) when acorns were sown under shrub, in comparison to the open, unprotected matrix. Facilitation of seedling growth by shrubs increased along the gradient of soil pollution, in agreement with the stress gradient hypothesis that predicts higher intensity of the facilitation effects with increasing abiotic stress. Although the accumulation of trace elements in seedling leaves was higher underneath shrub, the shading conditions provided by the shrub canopy allowed seedlings to cope with the toxicity provoked by the concurrence of low pH and high trace element concentrations in the most polluted sites. Our results show that the use of shrubs as nurse plants is a promising tool for the cost-effective afforestation of polluted lands under Mediterranean conditions. Keywordsthe research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement n° 603498 (RECARE), and from the Regional Ministry of Environment (Junta de Andalucía) within the SECOVER and ANASINQUE projects (PGC2010-RNM-5782). M.T.D. was supported by a Juan de la Cierva postdoctoral grant awarded to by the Spanish Ministry of Economy and Competitiveness. We are grateful to José María Alegre for his help at different stages of the study.Peer reviewe

Efecto facilitador de matorrales en la forestación de suelos contaminados por elementos traza

Póster y comunicación oral presentados en la Sesión 1: Soil conservation and restoration and soil pollution, del citado Congreso, celebrado del 1-4, julio, 2013, en Valencia, España.La forestación de zonas degradadas por la minería es particularmente importante en la cuenca Mediterránea, ya que las perspectivas futuras de cambio global prevén un aumento de los riesgos de erosión y desertificación, lo cual aumentaría la probabilidad de exportar elementos tóxicos a zonas colindantes. La contaminación del suelo por ciertos elementos tóxicos (como algunos elementos traza) puede ser un factor añadido a la dificultad de forestar estas áreas. Durante la última década hemos analizado algunos de los procesos clave para la restauración ecológica de la zona afectada por el accidente minero de Aznalcóllar (Sevilla) en 1998.Consejería de Medio Ambiente de la Junta de Andalucía, a través del proyecto SECOVER.Peer reviewe

Effects of soil contamination by trace elements on white poplar progeny: seed germination and seedling vigour

11 páginas.-- 2 figuras.-- 2 tablas.-- 62 referencias.-- Electronic supplementary material in the online version of this article (doi:10.​1007/​s10661-015-4893-8) contains supplementary material, which is available to authorized users.Seed germination is considered a critical phase in plant development and relatively sensitive to heavy metals. White poplar (Populus alba) trees tend to accumulate Cd and Zn in their tissues. We tested if soil contamination can affect P. alba progeny, reduced seed germination and explored the distribution of mineral elements in the seed. For this purpose, fruits and seeds from female P. alba trees were selected from two contaminated and one non-contaminated areas. Seeds from all the sites were germinated using only water or a nutritive solution (in vitro). Concentrations of nutrients and trace elements in the fruits and seeds were analysed. Seedling growth in vitro was also analysed. Finally, a mapping of different elements within the poplar seed was obtained by particle-induced X-ray emission (PIXE). Germination was similar between different progenies, refuting our hypothesis that seeds from a contaminated origin would have reduced germination capacity compared to those from a non-contaminated site. Seedling growth was not affected by the contaminated origin. Cadmium and Zn concentrations in fruits produced by P. alba trees in the contaminated sites were higher than by those from the non-contaminated site. However, the nutritional status of the trees was adequate in both cases. Cd in seedlings was higher in those from contaminated soils although lower than in fruits, indicating a certain exclusion from seeds. Preliminary results of the PIXE technique showed that Al and Zn were distributed uniformly in the seeds (Cd was not detected with this technique), while the nutrients P and S were concentrated in the cotyledons.We thank JM Alegre for helping in the field work and Patricia Puente for helping in the lab work.We thank the National Accelerator Centre (CNA) of Seville for the analytical facilities. This study was supported by CGL2011-30285-C02 project, funded by the CICYT of the Spanish Ministerio de Ciencia e Innovación and European FEDER funds.Peer reviewe

Geranium's response to compost based substrates

8 páginas, 2 figuras, 3 tablas, 10 referencias.-- International Symposium on Composting and use of Composted Materials for Horticulture, celebrado del 5-11 de abril 1997, en Ayr, Scotland, United Kingdom.The effects of compost based substrates on growth and nutrition of geranium (Pelargonium zonale cv Lucky Break F2) were investigated. Substrates of manure compost, cotton gin trash compost, municipal solid waste compost and pine bark utilized as potting media for domestic use, produced an underdevelopment of geranium plants with respect to the control. This behaviour is related to the inferior physical properties of the compost-based potting media, nitro gen immobilization due to the high C/N ratio of pine bark, and probably lack of available phosphorus originated by high calcium and high pH of the compost-based media. Nitrogen fertilization and a longer period of cultivation diminished the differences between plants grown in the control and in compost-based media. Plants grown in compost mixtures which were rich in K showed K and Ca leaf contents closer to the optimum range than did control plants.This work was supported by the Agencia de Medio Ambiente of the Junta de Andalucía and by Fertilizantes Orgánicos Melguizo, S. L.Peer reviewe