Effects of different fertilization patterns on soil microbial communities and carbon sequestration pathways in tea gardens
Organic and biological fertilizers impact soil microbial communities and nutrient cycling in tea gardens. The influence of fertilization methods, like broadcast versus furrow application modify microbial pathways of soil carbon sequestration remains unclear. We implemented five treatments: no fertilization, organic fertilizer broadcast application , organic fertilizer furrow application, biological fertilizer broadcast application and biological fertilizer furrow application. Using metagenomics, we examined how soil nutrients, soil organic carbon fractions and microbial communities relate to microbial carbon fixation pathways in tea garden soils under these fertilization regimes. The treatments with organic and microbial fertilizers significantly increased soil total nitrogen , available nitrogen and pH. Broadcasting applications also led to a significant rise in SOC. Redundancy analysis and Mantel tests showed that TN, available potassium and pH were the main drivers of the soil bacterial community, whereas AK, Easily oxidizable carbon and SOC primarily influenced the fungal community. Acidobacteriota and Actinobacteriota were significantly negatively correlated with most carbon fixation pathways. Proteobacteria and Gemmatimonadota showed significant positive correlations with the reductive citric acid cycle . The reducing citric acid cycle is the main pathway for microbe-mediated SOC immobilization. Particulate organic carbonand pH were the primary environmental factors influencing the abundance of microbial carbon-fixation genes. This study investigates the impact of organic and biological fertilizers on the microbial community involved in carbon sequestration in tea gardens, offering insights into soil nutrient cycling and microbial carbon sequestration mechanisms in this context.