Toward Sustainable Fertilizer Use: Fundamental Analysis of Ashes from Bamboo By-Products

Abstract

Bamboo is increasingly recognized as a sustainable biomass resource, supporting the global transition toward renewable raw materials for construction, landscaping, pulp and cellulose production, and high-performance bio-composites. However, intensive harvesting and processing leave behind substantial quantities of leaves, branches, and stem tips that are typically left in the field or incinerated, undermining the material’s overall environmental benefits. Valorizing these by-products is therefore essential to closing the bamboo value loop, yet systematic data on their composition and reuse options remain limited. To address this gap, this work examined the chemical compositions of the by-products (i.e., leaves and branches) of three bamboo species  native to Korea —Giant Bamboo (Phyllostachys bambusoides), Henon Bamboo (P. nigra), and Moso Bamboo (P. edulis)—and characterized the ashes obtained after controlled combustion. All ashes were strongly alkaline (pH 10 to 11) and exceptionally rich in plant-essential nutrients (K, Ca, Mg and P). This is particularly significant, as it is the first study to demonstrate that bamboo by-product ash is a nutrient-dense material with inherent liming properties, making it suitable for use as a fertilizer or soil amendment. These findings lay an important foundation for the future agricultural and industrial utilization of bamboo residues.