Sprayable starch films for agricultural mulching

Abstract Environmental sustainability has driven research into the development of biodegradable materials to address ecological challenges. In this study, biodegradable sprayable films were produced from thermally gelatinized cassava starch suspensions (5% w/v) to explore their potential application as protective coatings for agricultural soils. Starch gelatinization process was optimized to evaluate their feasibility to be applied by the spraying technique. Results showed that it is necessary to carry out a previous dilution of the gelatinized suspensions (1:4) to be able to spray them and form a uniform layer on the soil. To enhance films properties, it were introduced bentonite particles (0, 5, and 10% w/w starch basis) as reinforcement and sodium tetraborate (0 and 3% w/w starch basis) as crosslinking agent. A uniform bentonite particles distribution within the starch matrix was observed and films exhibited capacity to block UV and visible radiation, especially in the photosynthetically active radiation range. Tensile and puncture tests revealed that bentonite and borax presence increased the final films resistance, and biodegradability of the films was confirmed through water solubility and composting tests. The comprehensive findings from this study provide crucial insights for the implementation of eco-conscious innovations in crop cultivation and soil management techniques.