A Grey Water Footprint assessment for pesticides applied in soils with grape cultivation in Mendoza (Argentina)

FARRERAS, V; LANA, N.B.; GOMEZ, M. L.

Congreso; VIII Congreso Argentino de la Sociedad de Toxicología y Química Ambiental; 2022

The growing risk of diffuse contamination of surface waters by agrochemicals has increased interest in quantifying environmental impacts on water sources. The indicator used toevaluate these impacts is the Grey Water Footprint (GWF), which measures the amount ofwater necessary to assimilate a pollutant load produced from anthropic activity. In viticulture,for example, the estimation of the GWF can be employed for assessing the environmentalimpacts related to the use of pesticides. In the framework of the Institutional Analysis ofWater Management in Mendoza project, the GWF for a wide range of pesticides commonlyapplied in grape cultivation in the Fifth Irrigation Zone of Mendoza River were estimated. Todo this, we used information on (1) trade data about phytosanitary products for the period2018-2021, (2) surface with grape cultivation specifying the conduction system of the vine(?parral? or vineyard), and (3) crop yield. The spatial heterogeneity of the input data wasperformed at the district scale. For estimation of the GWF, chemical properties of eachpesticide (Koc and half-life in days), environmental factors (texture and organic mattercontent of soil, rain intensity and precipitation) and management practices in grapecultivation were taken into account. The results show that the total annual average ofpesticides load entering a water body from soils with grape cultivation (14,496 ha) duringthe 2018-2021period was 0.37 t year -1. The pesticide load was higher in crops with aconduction system of the vine through ?parral? with 56.24% of the total pesticide load. Themost critical chemical substance in the range of pesticides commonly applied to soils withgrape cultivation was Fluroxypyr-meptyl, requiring 196 million m3 year -1 of water toassimilate the pollutant load entering a water body. In general, diluting pesticide laden in awater body requires relatively more water when conduction system of the vine is through?parral? compared to conduction system through vineyards. At the district level, the findingsreport a large diversity of GWF among different phytosanitary products, indicating theimportance of considering all of them when seeking to protect surface waters and groundwater based on a GWF assessment. These results may be of particular use for stakeholdersinterested in making the viticulture more sustainable.