Development of biodegradable pots from different agroindustrial wastes and byproducts

Abstract

Biodegradable pots for seedling growth were developed from biocomposites based on different byproducts and solid wastes such as gelatin, corn- and wheat-waste flour, sunflower seed husks and rice husks, yerba mate waste and used paper. Water absorption, solubility, tensile and biodegradation tests were carried out to determine physical and mechanical properties of studied biocomposites. Moreover, a direct test with plants was performed during summer months to evaluate the growth of pepper seedlings (C. baccatum) within the biocontainers. Results showed that gelatin-based biocomposites reached the higher solubility and water absorption. After 24 days, wheat- and corn-waste flour formulations biodegraded 28.5 and 27%, meanwhile, gelatin had the most decomposition rate (62%) and paper-based biocomposites, the least (25%). Gelatin based formulations supported the maximum load in tensile tests, although flexural tests showed that paper-based biocomposites are the most flexible. From the field test it was observed that gelatin biocontainers were almost degraded at the first week and also allowed the greatest plant development, acting as fertilizer, even better than the control plant. On the contrary, plant growth in biocontainers based on wheat- and corn-waste flour as well as paper was impeded since the low level of container decomposition. As a consequence, all formulations prepared have proved biodegradation. Gelatin-based containers could be considered as plantable, while the other ones must be considered as compostable.