Soil nitrogen deposition calculation for determining its incidence in terrestrial eutrophization in Mendoza Argentina

ARENA, AP Y CIVIT B

Zurich, Suiza

Conferencia; 3rd International Conference on Life Cycle Management LCM 2007; 2007

ETH Zurich

While the use of LCA in developing countries is increasing, the awareness about the limitations of the most widespread LCA methodologies and tools should be raised in order to avoid misleading conclusions, at the same time as the local knowledge is being built up. With this aim during the last year a work has been carried out for studying the influence of using very well known LCIA methodologies in the regional context, comparing their outcomes with the results obtained using regional characterization factors developed for different impact categories for the arid region of western Argentina. In this paper we present and discuss the model used for calculating the soil Nitrogen deposition in Mendoza (Argentina). In this phase only the NOx emissions are taken into account, considering both fixed and mobile sources for the calculus of the annual concentration in mg/m3, which was obtained using the ISC 3 program (US EPA). The main fixed sources are located in the Lujan de Cuyo Industrial Park, while for the mobile sources the vehicular traffic in the metropolitan area of Mendoza is considered. The annual concentration is then converted into deposition index, which values are then used in a Geographic Information System - GIS (ArcView 3.2®). The deposition is then compared with the threshold calculated for garlic, a typical agricultural product of the Argentinean western arid region. This product has been chosen due to its economic importance, the covered area, and the available information regarding its production management and annual yields. The garlic sensibility to eutrophization is established according to the Nitrogen threshold values that the product can cope with without relevant declination in its annual yield. The threshold value for garlic was found to be 297 Kg N ha-1 (Gaviola and Lipinski 2002). It must be considered that the region is characterized by soils with Nitrogen deficiencies (200 – 600 mg·kg-1) (Gaviola et al, 1998; Gaviola et al, 1991). The Nitrogen deficiency should be provided by fertilizers. In these conditions, the Nitrogen deposition is not provoking eutrophization until the threshold value is reached