Obtenção de microrganismos solubilizadores com potencial valor ecológico para uma agricultura sustentável

Mestrado em Engenharia do Ambiente - Instituto Superior de AgronomiaThere is a growing awareness about environmental impacts associated with the use of large amounts of inorganic fertilizers, not only in Portugal, but worldwide. Plants require available nutrients to meet their metabolic needs, so that they can grow appropriately and sustain an increasing global population. Soil microorganisms play fundamental roles in biogeochemical cycles due to their ability to produce specific enzymes, organic acids and other organic compounds that are required to mobilize nutrients. These may be present in available forms, but mostly they are unavailable to plants, including many inorganic and organic, soluble or insoluble forms. Cellulose, phytates, some phosphates and sulfonates are examples of carbon, phosphorus and sulphur-containing compounds, respectively, that are not directly available to plants. Cycling of these nutrients may be enhanced by the application of microbial consortia to soils. The present study may contribute towards a more sustainable agriculture through the selection of soil microorganisms with the capacity to mobilize nutrients which would be otherwise unavailable to plants. Such consortia can be considered as a biofertilizer. With the use of the selected microorganisms it may be possible to achieve a greater nutrient use efficiency of fertilizers applied to soils, or even of nutrients already present in soils in unavailable forms, thus contributing to better soil management practices