TITLE:
Chlorella Residue Functions as a Bio-Stimulant to Promote Plant Growth and Improve Soil Fertility
AUTHORS:
Asuka Okazaki, Toru Mizoguchi, Zakirul Islam, Quoc Thinh Tran, Motoki Kubo
KEYWORDS:
Bacterial Biomass, Bacterial Diversity, Chlorella Residue, Clubroot Disease, Plant Disease
JOURNAL NAME:
Journal of Agricultural Chemistry and Environment,
Vol.13 No.4,
November
5,
2024
ABSTRACT: Chlorella residues are currently underutilized. Therefore, in this study, we analyzed the nutritional components of Chlorella residue, and investigated its potential use as an organic fertilizer/bio-stimulant. Composition analyses revealed that the Chlorella residue contained a substantial amount of nitrogen (97,910 mg/kg), and significant quantities of secondary macronutrients, such as calcium (4300 mg/kg) and magnesium (9700 mg/kg), and micronutrients, such as iron (1850 mg/L) and manganese (359 mg/kg). The application of Chlorella residue to soil resulted in increased soil bacterial biomass. When Chlorella residue was added to the soil at a rate of 0.5% or 1.0% (w/w), the fresh weights of Brassica rapa and Spinacia oleracea were significantly increased. Furthermore, the application of Chlorella residue to the soil of B. rapa suppressed the reduction of the microbiome caused by clubroot disease and decreased the clubroot disease index. Therefore, Chlorella residue can be included in organic fertilizers that effectively improve soil nutrient contents, promote plant growth, and reduce the incidence of disease.