Groundwater nitrate contamination and agricultural land use: A grey water footprint perspective in Southern Apulia Region (Italy)

In this paper, we present a new approach based on the Grey Water Footprint (GWF) concept for the determina- tion of groundwater nitrate contamination, with a focus on the agricultural impact in the Southern Apulia Region (Italy). The GWF assessment allows us to highlight wells where nitrate contamination is higher and for which a veri fi cation of the nature of contamination is necessary, potentially identifying certain contexts associated with risk factors present in the area. Data show higher nitrate GWF values for vineyards than for olive groves, partic- ularly in areas used for the production of table grapes. Indeed, it is possible to observe that the Western Ionian- Tarantino arch is characterized by a high average level of the GWF indicator, area characterized by an agricultural land use (vineyards, orchards, simple arable land). Another important area is the Brindisi plain, predominantly characterized by an agricultural vocation and a related fertilizer use. The situation in the whole Salento peninsula is more heterogeneous. The results of the GWF show high values in equally distributed points with a clear fre- quency in the coastal areas of the Ionic arch (Eastern Tarantino and Salento). The Water Footprint methodology and inparticular the GWF approach usedinthis studyconceives a useful indicator for the agricultural policy plan- ning processes, a criterion to establish land use management according to the status of hydrological basin and a tool for assessing the pollution monitoring programs