9 research outputs found

    Nitrogen fertilizer recommendations for sweet pepper crop in greenhouses of Campo de Cartagena

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    [SPA] En el año 1999 se diseñó un experimento en 8 lisímetros de drenaje de 7x7x0,90 m3 bajo invernadero, para estudiar la lixiviación de nitratos en un cultivo de pimiento. Desde el año 1999 hasta 2001 se han ensayado diferentes dosis de abonado mineral nitrogenado y desde el año 2002 hasta el 2006 diferentes técnicas de cultivo (ecológico, integrado y convencional), que han permitido evaluar las pérdidas de nitratos en el drenaje y obtener conclusiones sobre la producción, extrapolables a condiciones similares de suelo de la Comarca del Campo de Cartagena. Teniendo en cuenta los aportes de N del estiércol, el suelo y el agua y como resultado del estudio, se concluyó que con dosis de 1,5 UF de N mineral por tonelada de producción prevista (15 g N/m2 ) para una producción de 10 Tm/Ha (la media en la Comarca), combinado con el aporte de 4 kg de estiércol/m2, era suficiente para obtener buenas producciones con menor impacto medioambiental en comparación con las que se aplican en la Comarca y que están entre los 30 y 40 g N/m2. [ENG] In 1999 an experiment was designed in a greenhouse with eight drainage lysimeters (7x7x0.90 m) to study nitrate leaching in a sweet pepper crop. From 1999 to 2001 we tested different doses of mineral nitrogen fertilization and from 2002 to 2006 different farming techniques (organic, integrated and conventional). The aim of those experiments was to assess losses of nitrates from drainages and to study crop yield response as representative soil conditions in the region (Campo de Cartagena, Murcia, Spain). According to N supply, soil characteristics and water composition, we concluded that the supply of 15 g of N per m2, with the addition of 4 kg of manure was enough to maintain similar yield (10 t per ha) compared with traditional N-fertilizer practices in the region (30-40 g per m2). Our results can help to reduce the environmental impact of this crop.Esta investigación ha sido financiada por el INIA y el IMIDA Se agradece su colaboración en la cesión de los terrenos al Centro Integrado de Formación y Experiencias Agrarias de Torre-Pacheco (Murcia)

    Balance de agua y nitrógeno en un cultivo de pimiento grueso en el Campo de Cartagena

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    Se diseñó un experimento consistente en la construcción de 8 lisímetros de drenaje bajo invernadero en Torre‐Pacheco. En los años 2003, 2004, 2005 y 2006 se ensayaron en dicho invernadero tres técnicas de cultivo diferentes (T‐E:ecológico, T‐I:integrado y T‐C:convencional) en pimiento grueso, que han permitido, contando con la información obtenida durante cuatro años sobre abonado nitrogenado y riego, evaluar las pérdidas de nitratos en el agua de drenaje. Los resultados permiten comprobar como es la relación entre el nitrógeno aportado y el lixiviado para los sistemas de cultivo estudiados, corroborando como una mayor cantidad de abonado se corresponde con una lixiviación de nitrógeno mayor, para las mismas dosis de riego; pero sin perder de vista que en las parcelas testigo, sin aportación de nitrógeno mineral, se han medido considerables lixiviaciones de nitratos, aunque menores que en las parcelas con abonado mineral. Durante el desarrollo de esta investigación se ha comprobado, además, que una disminución de las dosis de nitrógeno respecto a las normalmente utilizadas en la zona de estudio produce cosechas similares. La dosis de 15 g N/m2 de abono mineral (nitrato cálcico + nitrato potásico) combinada con el aporte de 4 kg/m2 de estiércol fermentado se ha mostrado como la más eficaz en relación con la producción. Todo ello indica que el tratamiento T‐E acompañado de aportes adicionales de nitrógeno mineral, inferiores a los realizados en los T‐I y T‐C, constituiría una fertilización óptima que aseguraría la producción y longevidad del cultivo de pimiento.Esta investigación ha sido financiada por el INIA durante los años 2004, 2005 y 2006 (Proyecto RTA‐04‐035, en colaboración con la Comunidad Autónoma) y el resto de los años con fondos propios del IMIDA. Se agradece su colaboración en la cesión de los terrenos al Centro Integrado de Formación y Experiencias Agrarias de Torre‐ Pacheco (Murcia)

    Ecology and application of haloalkaliphilic anaerobic microbial communities

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    Haloalkaliphilic microorganisms that grow optimally at high-pH and high-salinity conditions can be found in natural environments such as soda lakes. These globally spread lakes harbour interesting anaerobic microorganisms that have the potential of being applied in existing technologies or create new opportunities. In this review, we discuss the potential application of haloalkaliphilic anaerobic microbial communities in the fermentation of lignocellulosic feedstocks material subjected to an alkaline pre-treatment, methane production and sulfur removal technology. Also, the general advantages of operation at haloalkaline conditions, such as low volatile fatty acid and sulfide toxicity, are addressed. Finally, an outlook into the main challenges like ammonia toxicity and lack of aggregation is provided.This work was performed in the TTIW- cooperation framework of Wetsus, European Centre of Excel- lence for Sustainable Water Technology (www.wetsus.nl). Wetsus is funded by the Dutch Ministry of Economic Affairs, the European Union Regional Development Fund, the Province of Fryslân, the City of Leeuwarden and the EZ/Kompas program of the“ Samenwerkingsverband Noord-Nederland”. The authors would like to thank the participants of the research theme "Sulfur", namely Paqell, for fruitful discussions and financial suppor

    Pines

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    Pinus is the most important genus within the Family Pinaceae and also within the gymnosperms by the number of species (109 species recognized by Farjon 2001) and by its contribution to forest ecosystems. All pine species are evergreen trees or shrubs. They are widely distributed in the northern hemisphere, from tropical areas to northern areas in America and Eurasia. Their natural range reaches the equator only in Southeast Asia. In Africa, natural occurrences are confined to the Mediterranean basin. Pines grow at various elevations from sea level (not usual in tropical areas) to highlands. Two main regions of diversity are recorded, the most important one in Central America (43 species found in Mexico) and a secondary one in China. Some species have a very wide natural range (e.g., P. ponderosa, P. sylvestris). Pines are adapted to a wide range of ecological conditions: from tropical (e.g., P. merkusii, P. kesiya, P. tropicalis), temperate (e.g., P. pungens, P. thunbergii), and subalpine (e.g., P. albicaulis, P. cembra) to boreal (e.g., P. pumila) climates (Richardson and Rundel 1998, Burdon 2002). They can grow in quite pure stands or in mixed forest with other conifers or broadleaved trees. Some species are especially adapted to forest fires, e.g., P. banksiana, in which fire is virtually essential for cone opening and seed dispersal. They can grow in arid conditions, on alluvial plain soils, on sandy soils, on rocky soils, or on marsh soils. Trees of some species can have a very long life as in P. longaeva (more than 3,000 years)

    Comparative genomics reveals high biological diversity and specific adaptations in the industrially and medically important fungal genus Aspergillus

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    Background: The fungal genus Aspergillus is of critical importance to humankind. Species include those with industrial applications, important pathogens of humans, animals and crops, a source of potent carcinogenic contaminants of food, and an important genetic model. The genome sequences of eight aspergilli have already been explored to investigate aspects of fungal biology, raising questions about evolution and specialization within this genus. Results: We have generated genome sequences for ten novel, highly diverse Aspergillus species and compared these in detail to sister and more distant genera. Comparative studies of key aspects of fungal biology, including primary and secondary metabolism, stress response, biomass degradation, and signal transduction, revealed both conservation and diversity among the species. Observed genomic differences were validated with experimental studies. This revealed several highlights, such as the potential for sex in asexual species, organic acid production genes being a key feature of black aspergilli, alternative approaches for degrading plant biomass, and indications for the genetic basis of stress response. A genome-wide phylogenetic analysis demonstrated in detail the relationship of the newly genome sequenced species with other aspergilli. Conclusions: Many aspects of biological differences between fungal species cannot be explained by current knowledge obtained from genome sequences. The comparative genomics and experimental study, presented here, allows for the first time a genus-wide view of the biological diversity of the aspergilli and in many, but not all, cases linked genome differences to phenotype. Insights gained could be exploited for biotechnological and medical applications of fungi. © 2017 The Author(s)
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