Implementing a GIS-based digital atlas with different datasets for estimating the agricultural plastics environmental footprint
The agricultural sector has benefitted over the last century from several factors that have led to an exponential increase in its productive efficiency. The increasing use of new materials, such as plastics, has been one of the most important factors, as they have allowed for increased production in a simpler and more economical way. Various polymer types are used in different phases of the agricultural production cycle, but when their use is incorrectly managed, it can lead to serious environmental impacts. Plastic pollution, largely perceived by the public as a major risk factor that strongly impacts sea life and preservation, has an even higher negative impact on terrestrial ecosystems. Indeed, quantitative data about plastic contamination on agricultural soils are progressively emerging in alarming ways. One of the main contributors to this pollution involves the mismanagement of Agricultural Plastic Waste (APW), i.e., the residues from plastic material used to improve the productivity of agricultural crops - such as: greenhouse covers, mulching films, irrigation pipes, etc. Indeed, a wrong management of agricultural plastics during and after their working lives, may pollute the agricultural soil and aquifers by releasing macro-, micro-, and nano-plastics, which could also enter into the human food chain.
In this study, an applied and simplified methodology to quantify and manage agricultural plastics is proposed. The techniques used are based on a deductive approach, based on the quantification through the use of different remote-sensed datasets (orthophotos and satellite images) of the areas covered by plastics used for crop protection. Additionally, through an inductive approach, based on statistical data from the agricultural census of the administrative areas of the Italian provinces, an agricultural plastic coefficient (APC) has been proposed, implemented, and spatialized in a GIS environment, to produce a database of APW for each type of crop.
The study area chosen for the analysis here presented is a part of the Ionian Coast of Southern Italy, which includes the most important municipalities of the Basilicata Region as for fruit and vegetable production. The use of geographical techniques and observation methodologies, developed in an open-source GIS environment, enabled an accurate location of about 2000 hectares of agricultural land covered by plastics, as well as the identification of areas most susceptible to the accumulation of plastic waste. The proposed methodology can be exported to other countries, since it represents valuable support that could realize, in integration with other tools, a database of agricultural plastics use, which may be a starting point to plan strategies and actions targeted to the reduction of the plastic footprint of agriculture. The techniques and the model implemented, due to its simplicity of use and reliability, can be applied by different local authorities, in order to create an atlas of agricultural plastics, which would be applied for their continuous monitoring, thereby enabling to upscale future social and ecological impact assessments, identification of new policy impacts, market searches, etc. as well.