INTECH   27907
INSTITUTO TECNOLOGICO DE CHASCOMUS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Maximizing Biological Nitrogen Fixation By Pasture Legumes In Acidic Soils
Autor/es:
COLAVOLPE B.; RUIZ O.A.; VIDEIRA E CASTRO, I.; MUÑOZ O.; PEREIRA P.; CARVALHO M.; SOARES R.; FARELEIRA P.; ALHO L.
Lugar:
MADRID
Reunión:
Congreso; XVII National Meeting of the Spanish Society of Nitrogen Fixation; 2019
Institución organizadora:
SOCIEDAD ESPAÑOLA DE FIJACIÓN BIOLÓGICA DEL NITRÓGENO
Resumen:
Montado, is an agro-silvo-pastoral ecosystem dominated by cork and holm oaks that combines the exploitation of cork with livestock husbandry, pastures and other uses. In Portugal in the Montado ecosystems, soils have commonly low fertility and are generally acidic with high concentrations of aluminium (Al) and manganese (Mn). Soil acidity restricts agricultural production by around 70% in potentially arable lands worldwide, mainly due to the effects associated with Al(III) and Mn(II) toxicity on plant growth. Pasture legumes are among the most efficient leguminous plants in terms of nitrogen fixation and contribute to high input rates of fixed nitrogen into the soil (Castro et al., 2016). Therefore, legumes and bacteria of the respective root nodules are considered as a management tool to improve pasture yield in Montado.The prolonged exposure to high concentrations of Al and Mn have a negative impact in the pastures yield in these agro ecosystems. In this context, as Montado soils are not out of this problematic, legumes and bacteria of the respective root nodules with high efficient in nitrogen fixing capacity and relative tolerance to Al(III) and Mn(II) can probably be a management tool for improving pasture yield in this types of soils.For this study, bacteria were isolated from root nodules of different Trifolium species grown in controlled-environmental conditions and previously inoculated with soil suspensions from a field essay installed in an acidic soil (Arenosol) under Montado and also in the presence or absence of soil correctives, such as dolomitic limestone and cellulosic sludge.This work aimed to study the genetic diversity of rhizobial population, evaluate nitrogen fixing capacity of rhizobia isolates and their identification by 16S rDNA sequencing and also analyse other important characteristics such as Al(III) and Mn(II) tolerance and their motility by swimming tests in agar medium. All these tests contribute to select rhizobia strains adapted to acidic soils showing our results the existence of a group of strains with these characteristics which could be used in a future development of an adapted inoculant to annual Trifollium species in Montado with these characteristics.