Agronomía

URI permanente para esta comunidadhttps://hdl.handle.net/11441/11296

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Examinando Agronomía por Agencia financiadora "Generalitat de Catalunya"

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    Acceso AbiertoPonencia
    Análisis técnico-económico de los sistemas caprinos lecheros de raza malagueña
    (2013) Romero, I.; Gutiérrez, R.; Ruiz Morales, Francisco de Asís; Mena Guerrero, Yolanda; Universidad de Sevilla. Departamento de Ciencias Agroforestales; Alcalde Aldea, María Jesús; Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA); Generalitat de Catalunya; Universidad de Sevilla. AGR-233 Tecnología de la Producción Animal
    Se ha realizado un análisis técnico-económico correspondiente al año 2011, de una muestra de explotaciones caprinas de raza Malagueña. Todas las explotaciones analizadas poseen base territorial, la cual destinan en su mayoría a la siembra de forrajes para su posterior aporte en pesebre. Se observa una clara tendencia de los ganaderos a tratar de igualar el aporte de concentrados y de forrajes a las cabras, lo cual se ha visto que conlleva resultados, tanto productivos como económicos, positivos. Si bien el Margen neto obtenido por trabajador familiar, sin considerar el coste de amortización, es aceptable y ha aumentado ligeramente respecto a 2004, los costes de producción en 2011 son elevados, de forma que el coste del litro de leche vendido superó en 4 céntimos el precio pagado por dicho litro.
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    Acceso AbiertoArtículo
    Isotopic methods for non-destructive assessment of carbon dynamics in shrublands under long-term climate change manipulation
    (Wiley, 2018) Andresen, Louise C.; Domínguez Núñez, María Teresa; Reinsch, Sabine; Smith, Andrew R.; Schmidt, Inger K.; Ambus, Per; Tietema, Albert; Universidad de Sevilla. Departamento de Cristalografía, Mineralogía y Química Agrícola; European Commission (EC); Gobierno de España; Generalitat de Catalunya; European Research Council (ERC); Hungarian Scientific Research Fund. Hungría
    Long-term climate change experiments are extremely valuable for studying ecosystem responses to environmental change. Examination of the vegetation and the soil should be non-destructive to guarantee long-term research. In this paper, we review field methods using isotope techniques for assessing carbon dynamics in the plant–soil–air continuum, based on recent field experience and examples from a European climate change manipulation network. Eight European semi-natural shrubland ecosystems were exposed to warming and drought manipulations. One field site was additionally exposed to elevated atmospheric CO2. We discuss the isotope methods that were used across the network to evaluate carbon fluxes and ecosystem responses, including: (1) analysis of the naturally rare isotopes of carbon (13C and 14C) and nitrogen (15N); (2) use of in situ pulse labelling with 13CO2, soil injections of 13C- and 15N-enriched substrates, or continuous labelling by free air carbon dioxide enrichment (FACE) and (3) manipulation of isotopic composition of soil substrates (14C) in laboratory-based studies. The natural 14C signature of soil respiration gave insight into a possible long-term shift in the partitioning between the decomposition of young and old soil carbon sources. Contrastingly, the stable isotopes 13C and 15N were used for shorter-term processes, as the residence time in a certain compartment of the stable isotope label signal is limited. The use of labelled carbon-compounds to study carbon mineralisation by soil micro-organisms enabled to determine the long-term effect of climate change on microbial carbon uptake kinetics and turnover. Based on the experience with the experimental work, we provide recommendations for the application of the reviewed methods to study carbon fluxes in the plant–soil–air continuum in climate change experiments. 13C-labelling techniques exert minimal physical disturbances, however, the dilution of the applied isotopic signal can be challenging. In addition, the contamination of the field site with excess 13C or 14C can be a problem for subsequent natural abundance (14C and 13C) or label studies. The use of slight changes in carbon and nitrogen natural abundance does not present problems related to potential dilution or contamination risks, but the usefulness depends on the fractionation rate of the studied processes.