Effects of Long-Term Application of Earthworm Bio-Organic Fertilization Technology on Soil Quality and Organo-Mineral Complex in Tea Garden

Soil quality is crucial for plant productivity and environmental quality sustainability. Applying bio-organic fertilizer to achieve sustainable agriculture has become popular. Tea garden soil which had been fertilized for 12 years was chosen for the study, and soil quality and microaggregate composition were studied. The results showed that earthworm bio-organic fertilizer treatment could increase the indicators of soil's physical and chemical properties such as total carbon and total nitrogen in soil. Bio-organic fertilization technology could significantly increase the number and activity of soil microorganisms, and upgrade soil enzyme activity which was related to soil nutrients. Specifically, the activities of urease in soil were markedly enhanced due to the implication of bio-organic fertilizer. Additionally, SR-FTIR analysis revealed that clay minerals were connected as nuclei with the capacity to bind carbon, and that this interaction was aided by organic fertilization. Specifically, the replacement of chemical fertilizer with organic fertilizer can improve the ability of clay minerals and iron/aluminum/silicon oxides to protect aliphatic groups, polysaccharides and proteins. In conclusion, continuous organic amendments initialize a positive feedback loop for the maintenance of the organic-mineral complex in soils, which can contribute to enhanced soil organic carbon (SOC) storage. These results confirmed the feasibility of organic fertilizer for soil quality improvement in tea plantation ecosystems.