Soil Solarization with biodegradable plastic films: Two years of experimental tests

Soil solarization is an “environmentally-friendly” pest and weed control method utilized in agriculture. While the use of plastic films for soil solarization provides for an increased level of agricultural productivity and a reduction in the use of chemicals, there is however a serious drawback regarding the disposal of used traditional plastic materials. A possible solution to this problem is the use of biodegradable plastics, which degrade gradually when plowed-down due to the action of microorganisms. Current trends towards the use of environmentally-friendly products have contributed to the commercial development of plastic materials based on renewable agricultural resources marketed as biodegradable. Examples are plastics based on starch, and synthetic polymers. The comparison between biodegradable, EVA based and coextruded multilayer films for soil solarization in field is the aim of this research. Field experiments were carried out from Febrary 2001 to July 2003. The climatic parameters and soil temperatures at different depths under each of these materials have been evaluated. Measuring the laceration, tensile strength and the radiometric properties every 15 days tested the performance of the materials. Soil samples were analysed in order to verify the reduction of infesting load soilborne pathogens. EVA and multilayer films produced higher soil temperatures, longer duration, and better phytopathological results were obtained in comparison to the biodegradable film. The reached thermal levels in the soil and the mortality of the pathogenic are enough comparable for the three material used. Therefore, the use of biodegradable films, if their radiometric and mechanical properties are improved, should be increased due to their high level of environmental compatibility.