Rhizoremediation strategies to comprehensively address agricultural pollution in Humid Pampa (Argentina)

MERINI, LJ

Syracuse

Conferencia; 10th International Phytotechnology Society Conference; 2013

International Phytotechnology Society - State University of New York College of Environmental Science and Forestry

Humid Pampa region is one of the most exploited and productive agricultural soils around the world. It is characterized by high humic matter content soils and its temperate Pampean weather. In this context, the environmental impact of agrochemical, associated to the intensive agriculture management, is addressed from different bio/phytoremediation biotechnological perspectives. Since the phytoremediation is a site specific technology, each aspect involved in the process have to be address. In this way, core soil samples were collected from sites representative of the intensive agriculture with records of the farming practices from the last 15 years. From those soils, microcosm assays were performed and herbicide degrading microorganisms were isolated and characterized. Two herbicide degrading consortia were isolated and the novel 4-(2,4-dichlorophenoxy) butyric acid-degrading bacterium Cupriavidus pampae sp. nov. was registered. Parallel, herbicide degradation and plant growing promoting capabilities of the consortia were assessed, in order to maximize plant establishing and rhizopheric degradation. Here, the atrazine degrading consortia proved to be phosphorous solubilizing. Further, tolerant vegetal species with the suitable agronomic profile were sought and their herbicide tolerance mechanisms investigated. The novel atrazine tolerant Lolium multiflorum (ryegrass) was found to be suitable for designing phytoremediation strategies specific for this region and its agricultural practices. Microcosm degradation tests demonstrated the potential of ryegrass for stimulating recalcitrant herbicides removal and field scale experiments were successfully carried out with it. Currently, the atrazine degrading/phosphorous solubilizing consortium is being immobilized in a natural polymeric matrix aiming to co-inoculate the ryegrass seeds in a field scale experiment.