Mineral Nutrients, Organic Amendment, and Water Impact Decomposition of Biodegradable Containers Under Controlled Conditions

Abstract

Laboratory studies were conducted to evaluate effect of soil water content, organic soil amendment, and mineral nutrient application on decomposition of three types of biodegradable containers: recycled paper, wood pulp fiber, and coconut coir over 182 days. Soil respiration was assessed through alkaline trap and titration method to determine decomposition of biodegradable containers. Percentage of carbon content remaining in the container material after 182 days was also quantified. Relative to soil water content, recycled paper containers under 40% water holding capacity (WHC) had higher carbon dioxide released than 60%WHC. Carbon analysis indicated that less carbon remained for all container types under 60% than 40%WHC. For recycled paper and coconut coir pots, treatments receiving container and soil amendment had significantly increased soil respiration. Post-experiment carbon analysis revealed less carbon remained in the recycled paper, wood pulp fiber, and coconut coir containers in the absence of organic soil amendment. For coconut coir, the interaction of container × mineral nutrients appeared to increase soil respiration with higher carbon dioxide released under biodegradable container × low mineral nutrient. This study suggests that cultural practices (i.e., irrigation and organic matter amendment) could facilitate degradation for certain biodegradable container types; however, to provide extensive cultural practice recommendations regarding biodegradable containers, more research is needed.