Response of soil biodiversity and crop productivity to liming in acidic soil of organic tea plantations in Northern Vietnam

In Northern Vietnam, farmers are converting significant areas of their allocated rice paddy fields into organic tea plantations to increase and diversify their income. Our previous study indicated that as tea soil is strongly acidic, suitable solutions such as lime application can help to mitigate soil acidity. However, to date, the impact of these strategies on soil chemical properties, soil biodiversity and crop productivity in tea farming has not been thoroughly investigated. This study examined how liming affects soil chemical and biological indicators using amplicon Illumina sequencing analyses, and crop productivity in organic tea farming with different land use histories. Nine months after applying lime, soil pH increased by 0.4 units, soil organic matter content by 0.28 %, and P availability by 23.1 mg/100 g while soil exchangeable Al and Mn were reduced. The abundance and composition of macrofauna in soil and organic mulch were altered by lime addition but were not significantly correlated to land use history. Liming also enhanced tea root mycorrhization by native arbuscular mycorrhizal fungi (AMF) and tea yield, regardless of land use history. Despite this, the relative abundance and composition of soil bacteria, fungi, and AMF showed a significant response to land use history rather than liming. This study provides valuable insights into how soil liming and land use history affect tea soil food webs, plant growth, and tea organic yields, and suggests that liming could be an effective strategy to improve acidic soils, restore soil biodiversity in these soils, and sustain crop productivity in this tropical region.