Hydrolyzed protein based materials for biodegradable spray mulching coatings

Low density polyethylene (LDPE) films are widespread used in agriculture for soil mulching. The use of LDPE mulching films causes the serious drawback of huge quantities of waste to be disposed of. Over the last years the growing environmental awareness has been prompting the research to develop a new generation of mulching products starting with raw materials from renewable origin. These materials have to retain their physical and mechanical properties while in use and have to be compostable or biodegradable at the end of their life, degrading via micro-organisms into carbon dioxide or methane, water and biomass. The research is focused on the development of novel biodegradable polymeric materials based on hydrolyzed proteins, derived from waste products of the leather industry. Biodegradable soil mulching coatings were realized with these biodegradable polymeric materials by means of spray techniques; the coatings were tested in a Ligustrum ovalifolium cultivation carried out inside a greenhouse. This paper describes the functionalities of the new bio-based mulching coatings, which were developed and tested in real scale greenhouse cultivation tests. During the trial, the biodegradable soil mulching materials showed suitable properties for an efficient and profitable use in agriculture. The innovative biodegradable spray coatings lasted up to 18 months. The biodegradable materials could be the environmentally friendly alternatives to synthetic petro-chemical polymers and could contribute to a sustainable agriculture

Production and characterisation of environmentally relevant microplastic test materials derived from agricultural plastics

Soil environments across the globe, particularly in agricultural settings, have now been shown to be contaminated with microplastics. Agricultural plastics – such as mulching films – are used in close or direct contact with soils and there is growing evidence demonstrating that they represent a potential source of microplastics. There is a demand to undertake fate and effects studies to understand the behaviour and potential long-term ecological risks of this contamination. Yet, there is a lack of test materials available for this purpose. This study describes the manufacture and characterisation of five large (1–40 kg) batches of microplastic test materials derived from agricultural mulching films. Batches were produced from either polyethylene-based conventional mulching films or starch-polybutadiene adipate terephthalate blend mulching films that are certified biodegradable in soil. Challenges encountered and overcome during the micronisation process provide valuable insights into the future of microplastic test material generation from these material types. This includes difficulties in micronising virgin polyethylene film materials. All five batches were subjected to a thorough physical and chemical characterisation - both of the original virgin films and the subsequent microplastic particles generated - including a screening for the presence of chemical additives. This is a critical step to provide essential information for interpreting particle fate or effects in scientific testing. Trade-offs between obtaining preferred particle typologies and time and cost constraints are elucidated. Several recommendations emerging from the experiences gained in this study are put forward to advance the research field towards greater harmonisation and utilisation of environmentally relevant test materials

Hydrolyzed protein based materials for biodegradable spray mulching coatings

4Low density polyethylene (LDPE) films are widespread used in agriculture for soil mulching. The use of LDPE mulching films causes the serious drawback of huge quantities of waste to be disposed of. Over the last years the growing environmental awareness has been prompting the research to develop a new generation of mulching products starting with raw materials from renewable origin. These materials have to retain their physical and mechanical properties while in use and have to be compostable or biodegradable at the end of their life, degrading via micro-organisms into carbon dioxide or methane, water and biomass. The research is focused on the development of novel biodegradable polymeric materials based on hydrolyzed proteins, derived from waste products of the leather industry. Biodegradable soil mulching coatings were realized with these biodegradable polymeric materials by means of spray techniques; the coatings were tested in a Ligustrum ovalifolium cultivation carried out inside a greenhouse. This paper describes the functionalities of the new bio-based mulching coatings, which were developed and tested in real scale greenhouse cultivation tests. During the trial, the biodegradable soil mulching materials showed suitable properties for an efficient and profitable use in agriculture. The innovative biodegradable spray coatings lasted up to 18 months. The biodegradable materials could be the environmentally friendly alternatives to synthetic petro-chemical polymers and could contribute to a sustainable agriculture.nonenoneE. Schettini; L. Sartore; M. Barbaglio; G. VoxE., Schettini; Sartore, Luciana; M., Barbaglio; G., Vo

Physical Properties of Innovative Spray Biodegradable Coatings for Soil Mulching in Greenhouse Cultivation

In order to overcome the serious drawback of huge quantities of plastic waste obtained at the end of the life of agricultural plastic mulching films, researches on innovative biodegradable materials have been developing. The paper examines a new sustainable approach in which a water solution of natural biodegradable polymers is sprayed on a cultivation area in order to form a mulch coating. The material used is a blend of two polysaccharides, such as Guar Gum and Locust Bean Gum additivated with glycerol. A protected field experiment was conducted to test the effectiveness of spray black biodegradable mulching coating in a tomato crop in Southern Italy. Field performance and physical properties, evaluated by means of laboratory tests, are compared to those of commercial low density polyethylene and biodegradable starch based mulch films. The spray mulching coating is opaque in the solar radiation range and behaved as a black body. The tested spray coating showed much lower values of tensile stress and elongation at break in comparison with the values of commercial low density polyethylene and biodegradable starch based mulch films. Such innovative coatings were characterised by functionality during their use in field. Results indicate that the biodegradable spray coatings could be a sustainable alternatives to plastic films based on fossil raw materials

Biodegradable polymeric materials based on hydrolyzed proteins for agricultural applications

Aim of the research is the development of biodegradable polymeric materials based on hydrolyzed proteins, derived from waste products of the leather industry. Soil mulching coatings, made with the biodegradable materials, were applied to the soil by means of spray techniques; the coatings were tested in an ornamental cultivation carried out inside a greenhouse. Containers for seedlings transplant were realized using the biodegradable materials; seedling production and post-plant performance were analyzed. The containers were tested in a pepper cultivation carried out inside the greenhouse. The innovative biodegradable spray coatings lasted in the field up to 9 months. The biodegradable containers for seedlings transplanting showed a good resistance during the first stage of use, when the seedlings were grown from the seeds before the transplanting; the biodegradable materials showed a soil fertilizing effect, due to the slow release of proteinaceous material, as a result of the biodegradation process

Effects of Agrochemicals on the Mechanical Properties of Plastic Films for Greenhouse Covering

Greenhouse plastic films are subjected to degradation due to their exposure to solar radiation and to agrochemicals used during cultivation. This results in a reduction of life, which ranges from some months to 3–4 years relative to the thickness of the plastic film and to the degree of stabilisation. A research was carried out in order to evaluate the variation of the mechanical properties of 4 different polyethylene-co-vinyl acetate (EVA) films exposed to the climatic agents and to agrochemicals used during cultivation. The test was carried out at the University of Bari (Italy) in 2006. Four EVA films, one without anti-UV additive and three experimental films with different anti-UV additives, were installed on steel arches of four low tunnels. The films were sprayed with agrochemicals containing iron, chlorine and sulphur. The same films, mounted over other four low tunnels, were not sprayed in order to be used as control. Mechanical laboratory tests were carried out on the film samples, taken at fixed time intervals in the field, in order to assess the variations of the stress and strain at break. The different anti-UV stabilizers influenced the behaviour of the films in presence of the sprayed agrochemicals. The tests showed that the highest resistance to the agrochemicals was recorded for the EVA film stabilized with NOR-HALS plus UV filter

Nuovi materiali polimerici biodegradabili da risorse rinnovabili

The aim of this paper is to describe the development and the application of novel biodegradable polymeric materials based on hydrolyzed proteins, derived from waste products of the leather industry, to be used in the agricultural application, in particular as biodegradable mulch spray coatings in horticulture and to create biodegradable containers for seedlings. Through the appropriate dosage of additives such as natural fibres, fillers, pigments and plasticizers, it is possible to modulate the physico-chemical and mechanical properties, and the mulching effect of films. Tests were carried out in order to prove the feasibility of the novel spray mulching coatings by investigating their functionality and the mechanical behavior in a standard and controlled experimental condition during the field test. The biodegradable containers for seedlings transplanting were tested in a field test; the seedlings, starting from the seeds, grew inside the innovative containers