Biodegradable films and spray coatings as eco-friendly alternative to petro-chemical derived mulching films (original) (raw)
Related papers
Acta Horticulturae, 2014
The use of plastic materials in agriculture causes the serious drawback of huge amount of wastes to be disposed of. In order to overcome this problem a new generation of biodegradable materials has been developed based on raw materials coming from renewable source. These materials retain their physical and mechanical properties during their lifetime and when they are integrated directly in the soil, the bacterial flora transforms them in carbon dioxide or methane, water and biomass. Biodegradable films can be made using natural polymers, such as starch, cellulose, chitosan, alginate and galactomannans. These materials can be obtained by means of thermoextrusion process, solvent casting and spraying technique. Mulch coatings can be realized directly in field by spraying water solutions based on natural polysaccharides, thus covering the cultivated soil with a protective thin geo-membrane. In this paper a focused overview on the formulation development, processing understanding, field performance and mechanical properties of these innovative materials for soil mulching is presented, in comparison to oil-based non renewable films. During their using time in field, the biodegradable mulches showed suitable mechanical properties if compared to the low density polyethylene films. At the end of their lifetime the biodegradable materials were shattered and buried into the soil together with plants. The film residues disposed of in the soil biodegraded in almost 1 month for the water borne coatings and in about 12 months for the biodegradable starch-based extruded films.
Starch-Based Films and Spray Coatings as Biodegradable Alternatives to Ldpe Mulching Films
International Symposium on High Technology for Greenhouse System Management: Greensys2007, 2008
Biodegradable starch-based extruded mulching films and biodegradable sprayable water-born polysaccharides based coatings were prepared within two European Projects as an alternative to soil mulching films made of synthetic petrochemical polymers. The biodegradable mulches, both films and coatings, had appropriate mechanical and physical properties to assure their functionality throughout the crop cycle in relation to the cultivation needs, the geographical region, and the season. The useful lifetime of the biodegradable films and coatings was fully comparable with the low density polyethylene films currently in use: the biodegradable films lasted up to 9 months, the biodegradable coatings up to 6 months. They satisfy the mulching task of weed control during the crop cycle reducing solar PAR radiation reaching the mulched soil and creating a physical barrier preventing airborne weed seeds.
Polymers Use as Mulch Films in Agriculture—A Review of History, Problems and Current Trends
Polymers
The application of mulch films for preserving soil moisture and preventing weed growth has been a part of agricultural practice for decades. Different materials have been used as mulch films, but polyethylene plastic has been considered most effective due to its excellent mechanical strength, low cost and ability to act as a barrier for sunlight and water. However, its use carries a risk of plastic pollution and health hazards, hence new laws have been passed to replace it completely with other materials over the next few years. Research to find out about new biodegradable polymers for this purpose has gained impetus in the past few years, driven by regulations and the United Nations Organization’s Sustainable Development Goals. The primary requisite for these polymers is biodegradability under natural climatic conditions without the production of any toxic residual compounds. Therefore, biodegradable polymers developed from fossil fuels, microorganisms, animals and plants are viabl...
Polymer Degradation and Stability, 2006
The use of plastic materials in agriculture causes the serious drawback of huge quantities of waste. The introduction of biodegradable materials, which can be disposed directly into the soil, can be one possible solution to this problem. Biodegradable materials are actually innovative materials; therefore, their physical properties must be evaluated in relation to their functionality during the use in field. In the present research results of experimental tests carried out on biodegradable films used in strawberries protected cultivation are presented. The decay of some relevant physical parameters of biodegradable films during the cultivation period was monitored by laboratory tests (SEM analysis, mechanical tensile tests and infrared reflectance spectroscopy). Infrared spectroscopy clearly indicated that the mechanical degradation starts from the starch component of the material. Tensile tests showed that the value of elongation at break of biodegradable materials decreased in some cases by 300% after 10 days of field application.
New Approach of Starch and Chitosan Films as Biodegradable Mulching
Revista Virtual de Química, 2019
Nova Abordagem dos Filmes de Amido e Quitosana como Mulching Biodegradável Resumo: Os polímeros amido e quitosana podem resultar em filmes biodegradáveis para reduzir a poluição por plástico no ambiente. A adição de quitosana pode melhorar as propriedades dos filmes de amido, bem como a adição de pigmentos auxilia no controle do crescimento de plantas invasoras. O objetivo do presente trabalho foi analisar o comportamento de filmes de amido/quitosana adicionados de pigmentos quando aplicados como mulching. Os valores de resistência a tensão na ruptura não variaram com a formulação, enquanto filmes adicionados com pigmentos foram mais flexíveis. A adição de quitosana reduziu em duas vezes a solubilidade dos filmes quando comparados aos filmes só de amido. Os filmes em contato com o solo apresentaram redução nas propriedades mecânicas, alterações no espectro no infravermelho e nas micrografias, no entanto os filmes não apresentaram fraturas visíveis por 45 dias. Os filmes de amido/quitosana serviram como mulching biodegradável.
Assessment of aliphatic–aromatic copolyester biodegradable mulch films. Part I: Field study
Chemosphere, 2008
The objective of this work was to study the use of new biodegradable films in agriculture under open field conditions. Three biodegradable mulch films made from modified biodegradable polyester of different thicknesses and colors (black and white) and a conventional low density polyethylene (LDPE) mulch film were used to cover the beds of tomato plants. Changes in physical appearance of the films were recorded as well as changes in their mechanical, optical, and physical properties. Once tomato harvest was completed, the conventional LDPE mulch film was removed and all the tomato plants were cut using a mower. The biodegradable mulch films were plowed into the soil. The change in the appearance of the film was recorded and samples of each film after plowing were characterized according to the properties mentioned above.
Preparation, characterisation and field-testing of a biodegradable sodium alginate-based spray mulch
Biosystems Engineering, 2009
An innovative biodegradable coating that can be sprayed was developed and tested as suitable alternative to low density polyethylene (LDPE) films for soil mulching in horticulture. A mulch was created by spraying onto the soil a sodium alginate water-based solution that, at the end of the cultivation cycle, could be tilled into the soil to be biodegraded. The mechanical and radiometric properties, the functionality of the spray coating, and its biodegradation were assessed by means of laboratory measurements and cultivation field tests. In the field, during the cultivation of strawberries, the spray coating was compared with a LDPE mulching film and a straw mulch. The mechanical properties of the coating degraded when exposed in the field, but the coating kept its mulching effect for 6 months. The radiometric properties varied without regular trends, but the coating maintained its capacity to suppress weeds. The biodegradation tests showed that the spray coating samples biodegraded by 65% after 6 months into the soil. (G. Vox).
Development of degradable slow-release multinutritional agricultural mulch film
Industrial & Engineering Chemistry Research, 1987
A novel agricultural mulch film is prepared by mixing conventional plant nutrients with a watersoluble polymer such as poly(viny1 alcohol). The release of the nutrients contained in the mulch film is controlled by the addition of nitrification inhibitor along with urea or the addition of water-soluble urea-formaldehyde polycondensate. Further control of the nutrient release is realized by the addition of a water-resistant coating layer such as poly(viny1 acetate) and other additives such as glycol, urea, and starch. The agricultural mulch film is degradable and has balanced properties. Although the mulch film is clear, it prevents weed growth. The mechanical properties,