Coir Fiber and Bamboo Vinegar Improve the Quality of Composted Green Waste as a Growing Medium for Peacock Arrowroot

Abstract

<jats:p>Composting is considered an environmentally sound and economically viable alternative for the management of organic residues. Although compost product may be used as a peat substitute in soilless culture, it generally has poor physical structure, low nutrient content, high pH, and high salt content. This study chose the coir fiber (CF) produced from coconut (<jats:italic>Cocos nucifera</jats:italic>) and bamboo vinegar (BV) produced from mottled bamboo (<jats:italic>Phyllostachys bambusoides</jats:italic>) as the media amendments, and evaluated the effects of CF (at 0%, 15%, and 25%) and/or BV (at 0%, 0.5%, and 1.0%) on the physical, chemical, and microbiological properties of composted green waste (CGW) and on the growth of peacock arrowroot (<jats:italic>Calathea makoyana</jats:italic>). The highest quality growing medium and the best growth of peacock arrowroot were obtained when CGW was amended with the combination of 15% CF and 0.5% BV; the lowest quality medium and the least plant growth were obtained with nonamended CGW. The optimal combination not only improved particle-size distribution and adjusted bulk density (BD), porosity, and water-holding capacity (WHC) into ideal ranges, but it also decreased pH and electrical conductivity (EC) and increased microbial numbers, enzyme activities, and macro- and micronutrient contents in the CGW. Relative to the nonamended CGW, the optimal CGW reduced the BD from 0.58 g·cm<jats:sup>−3</jats:sup> to 0.34 g·cm<jats:sup>−3</jats:sup> and the pH from 8.05 to 5.61, and increased the total porosity (TPS) from 48.1% to 77.0% and the WHC from 57.4% to 75.5%; the optimal CGW increased shoot fresh weight, shoot dry weight, root fresh weight, root dry weight, plant height, crown breadth, number of leaves, and total root length by 83.9%, 77.8%, 66.1%, 65.1%, 63.6%, 73.8%, 55.6%, and 65.2%, respectively.</jats:p>