Bioponic Innovation for Waste-to-Crop: Effects of Phosphorus and COD Concentrations on Microbial Community and Plant Productivity

Abstract

Bioponic systems is the combination of the organic waste compost with a closed recirculating hydroponic system to recover nutrients from organics fertilizer instead of hydroponic inorganic solutions. In bioponic systems, microorganisms transform organics nutrients to the bioavailable forms for plant use. This study investigated the microbial communities using Next – Generation Sequencing and examined the linking of microbial abundance to phosphorus and chemical oxygen demand (COD) by planting Romaine lettuce (Lettuca sativa, 18 plants/system) with chicken manure compost (250, 375, and 500 grams) in bioponic systems. From all of the experiments, the chicken manure loading rate of 500 g/18 plants (phase 2) had the highest phosphorus use efficiency (23.2%) and the highest plant dry weight (112.8 g/18 plants). The amount of chicken manure loadings (250 – 500 g) did not make different the total phosphorus concentration, the COD concentration and temperature in the long term. COD and phosphate concentrations were positively correlated (r=0.7177) as same as COD and total phosphorus concentration (r=0.6984). Furthermore, this study found the Actinobacteria (baterial phylum), WD2101_soil_group (bacterial family), Nocardiopsis, and Gemmata that were the dominant bacterial genera in bioponic system. These bacteria could facilitate phosphorus solubilization. This study also found JG30-KF-CM45 that was the dominant bacterial family in the water and the compost in chicken manure. It can degrade the organic carbon. The result of this study can improve the performance of chicken manure based bioponic systems for planting lettuce.