Implementation of GIS technologies for planning the valorisation of agricultural waste: the TANGO-Circular Project

The volume of waste produced by agricultural activities is constantly rising, due to the continuous increase of crop and livestock production, aimed to cover the nutritional needs of the accreting population of the Planet. According to recent estimations, the total amount of waste produced in the whole EU by the agricultural sector during the period 2010-2016, has been around 18.4 billion tons, which represents an average of 2.6 billion tons/year. This number is slightly exceeding the amount of waste from all other sectors combined. This enormous mass of waste has a significant environmental impact, which needs suitable solutions to reduce the carbon footprint of agriculture, while increasing the economic income for farmers. A promising way to reduce agricultural waste, passes through the valorization of agricultural co-products, by-products and residues, as well as other non-organic materials - such as plastics, widely used in crop cultivation and animal production - after the end of their working life. In order to involve farmers to play an active role on this issue, contributing to transform what they currently consider as a “waste” into a new “resource”, under the perspective of a circular economy and for a more sustainable agriculture, the Project TANGO-Circular has been financed by the EU Erasmus+ Programme. Aim of this Project is to train farmers and other agricultural stakeholders to be involved in finding viable solutions to exploit unusable remains of crops or animal farms, so as to enhance their financial input, while simultaneously contribute to reducing the environmental impact of their agro-livestock activities. With the aim to plan the valorization of agricultural waste, under the TANGO-Circular Project, a Geographical Information System (GIS) has been implemented through an open-access software (Q-GIS). This GIS has been structured into a first part dedicated to the quantification of agricultural waste flows – both organic, coming from agroindustrial activities, and not-organic, such as plastics - and a second part, focused on the spatial distribution of these flows in the study area of the project partners. Through GIS, the areas with high density of agricultural waste have been pointed out, and the suitable location of potential collection centres has been proposed. The maps that have been produced, as well as the GIS database, are always updatable tools, useful also for monitoring and optimizing the sorting and collection of agricultural waste from the farms, their suitable treatments and transport to the collection centers or recycling stations. The implemented GIS methodology has revealed very useful to support farmers and their associations, as well as all public bodies interested to govern the agricultural waste flows, to individuate possible solutions designed for the valorization of these flows, in the perspective of a circular economy. The sustainability and economic, territorial, environmental and social convenience of each form of valorization designed have been investigated, and criticalities associated with each phase of the process and consequent implementation of appropriate solutions to each problem have been addressed. Finally, further possible solutions, aimed at an increasingly better valorization of these flows, have been proposed as well

Biodegradable Plastic Mulch Films: Impacts on Soil Microbial Communities and Ecosystem Functions

Agricultural plastic mulch films are widely used in specialty crop production systems because of their agronomic benefits. Biodegradable plastic mulches (BDMs) offer an environmentally sustainable alternative to conventional polyethylene (PE) mulch. Unlike PE films, which need to be removed after use, BDMs are tilled into soil where they are expected to biodegrade. However, there remains considerable uncertainty about long-term impacts of BDM incorporation on soil ecosystems. BDMs potentially influence soil microbial communities in two ways: first, as a surface barrier prior to soil incorporation, indirectly affecting soil microclimate and atmosphere (similar to PE films) and second, after soil incorporation, as a direct input of physical fragments, which add carbon, microorganisms, additives, and adherent chemicals. This review summarizes the current literature on impacts of plastic mulches on soil biological and biogeochemical processes, with a special emphasis on BDMs. The combined findings indicated that when used as a surface barrier, plastic mulches altered soil microbial community composition and functioning via microclimate modification, though the nature of these alterations varied between studies. In addition, BDM incorporation into soil can result in enhanced microbial activity and enrichment of fungal taxa. This suggests that despite the fact that total carbon input from BDMs is minuscule, a stimulatory effect on microbial activity may ultimately affect soil organic matter dynamics. To address the current knowledge gaps, long term studies and a better understanding of impacts of BDMs on nutrient biogeochemistry are needed. These are critical to evaluating BDMs as they relate to soil health and agroecosystem sustainability

In vitro and in vivo antifungal activity of phosphite against Phytophthora parasitica in tomato

Phosphite is an alkaline salt of phosphorous acid. Its antifungal properties against some phytopathogenic fungi are increasingly valued in the context of a growing concern about the detrimental environmental effects of the standard biocides used to protect plants against pests and diseases. The purpose of this work was to analyze the in vitro and in vivo effect of phosphite in the development and evolution of Phytophthora parasitica on a tomato crop. The phosphite potential to limit and control the fungus growth was first established through an in vitro assay. In a second assay, in the greenhouse, tomato plants were transplanted into pots, in a substrate previously inoculated or not inoculated with the fungus mycelium. Inoculated and non-inoculated plants were sprayed with a range of phosphite concentrations (0, 0.9, 1.4, and 1.9 mg ml-1). The in vitro growth of the fungus mycelium was progressively restricted as phosphite concentration increased in the medium, and no fungus growth was detected with a phosphite concentration of 0.9 mg/ml. In the greenhouse assay, the development of the inoculated plants improved during the culture time when treated with phosphite, as was acknowledged by their higher chlorophyll content and by the values of stress indicators when compared with untreated plants. Moreover, the dry weight of the infected plants increased as the phosphite concentration was higher, and their maximum growth was obtained at 1.4 mg ml-1 phosphite. It is also noteworthy that, when compared to healthy plants, the infected plants increased their root to total weight ratio by 31.6% when treated with the highest phosphite concentration