Atrazine phytoremediation in Humid Pampa plots (Argentina) under intensive agriculture management

MERINI, LJ; MASSOT, F; CALABRO LOPEZ A; GIULIETTI, AM

Hasselt

Congreso; 9th International Phytotechnology Society Conference; 2012

International Phytotechnology Society

Humid Pampa, the main agricultural region in Argentina, covers about 600.000 Km2 largely dedicated to intensive agricultural practices. As one of the main world atrazine consumers (7000 tons/year), the need of developing biotechnological strategies to minimize the environmental impact associated to this herbicide application is evident. In order to achieve this aim, a pilot scale open field experiment was carried out to assess the phytoremediation performance of the recently reported atrazine tolerant ryegrass species (Lolium multiflorum) in a corn field. Accordingly, a 16 hectares field was selected in Ramallo city vicinity (30°40?35,2?? S ? 60°09?21,0?? W), as representative of the intensive agricultural practices of the region. Soil was sampled before sowing and 36 plots of 100 m2 were delimited in order to representatively cover the plot. Then, corn crop was conventionally sowed and 2 L.ha-1 of atrazine (Atrazine500-Dow) applied postemergence. After corn harvest, ryegrass was sowed at 22 Kg.ha-1 rate in a paired plots fashion. Composite core soil samples were monthly collected from every plot and separated in 5, +10 and +20 centimeters deep in order to assess either the horizontal or the vertical atrazine movement. Soil samples were extracted and atrazine and metabolites content analyzed by HPLC-UV. Parallel, soil agronomical properties were assessed. Results indicate that ryegrass implantation significantly improves atrazine degradation, soil agronomical properties and reduce the herbicide movement caused by rainfall. Concluding, the especially designed ryegrass intercropping strategy fits as biotechnological strategy for atrazine environmental impact associated to intensive agronomical practices of the region.