## 3 Results and Discussions
Thanks to the GIS environment, it is possible to perform these operations in iterative and consequential ways, with enormous gains in time and, above all, providing spatially explicit information that can be calibrated in relation to the starting database [36]. The realization of the database in the form of a spreadsheet is fundamental because it allows performing surveys and analyses at different levels without having to perform complicated operations and, therefore, it is not too difficult for those who do not have high knowledge about geospatial techniques. In this way, the methodology implemented can be easily replicated in an immediate manner in relation to the information to be obtained. Therefore, for all crops analyzed, the same method and technique of calculation of APW expressed in tons per year was applied. Spatialization by Italian provinces allowed us to map plastics for each of them, differentiating them by type, and then making the overall total of tons of plastic waste produced each year (Figure 4). The result is composed of four maps connected to a numerical database in which the province that produces a greater amount of plastic types and the one that produces more can be evaluated. In this way, in addition to providing data, the methodology can be the basis for the development of a complex computerized system to identify centers for the disposal of APW [41]. Given the dimensions of the data produced (Table A2), provinces that produce more than 2% of the total annually were arbitrarily chosen to produce a summary graph (Figure 5). In addition, the complete tabular database can be found in Appendix A.  
Figure 3: Example of calculation of total tons of plastic used in a year in the case of watermelon cultivation in open air. From the analysis, it is clear that the provinces of Latina and Salerno (Latium and Campania regions) have greater quantities of plastic in relation to the examined crops, and that in all cases, the plastic films have greater weight on the overall total. These data have already emerged from the information previously elaborated, but in this phase, they provided new information about the areas with the highest amounts of plastic, expanding the studies already present in the literature to the study areas of southern Italy [35; 36]. The main objective of this work was to create an open source GIS-based methodology to preliminarily quantify the potential APW present in a given territorial and administrative area, in a way that easily implements with commonly available data and, at the same time, provides data that can be used in subsequent monitoring or decision-making phases [42] for the protection of soil from pollution by micro- and nanoplastics [43]. This study shows how the GIS approach is essential for the smarter and sustainable management of agricultural activities as it can put together data that are apparently difficult to spatialize [44]. Secondly, it provides basic data on the management of plastics in Italy, as it is one of the areas that uses the most plastic (Agricultural Plastic Europe, 2021). This kind of analysis, even if on a very large scale, since it is one of the NUT3 regions, provides useful indications to public decision makers to address specific strategies and actions to manage agricultural plastic waste and support agri-food supply chains [45; 46]. Figure 4: Mapping of the plastics produced each year by the crops examined within the Italian provinces. Compared with a previous study carried out on the entire Italian territory, [30], it emerges that the data, although referring to different years and plastic products, are comparable and in the same order of magnitude. Indeed, the coefficient values found for most crops of about 0.15 kg m\({}^{2}\) per year are almost the same, particularly for greenhouse plastic film. On the other hand, mulching films and irrigation pipes show slightly different values. This can be explained by the fact that, over the years, the technical characteristics (thicknesses in particular) of the plastic products used have changed.