Long-Term Effect of Phosphorus Availability on Table Grapes' Root Microbiome and Phosphorus Uptake

Phosphorus (P) is a critical nutrient for vineyard However, the involvement of roots microbiome in P uptake, especially under deficiency conditions remain poorly understood. This study examined the impact of different P application levels on two table grape cultivars: the early-bearing green cultivar 'Early Sweet' and the late-bearing purple cultivar 'Crimson.' Grapevines were cultivated in 500 L lysimeters containing perlite as a growth medium and subjected to three P fertigation treatments (1, 5, and 15 ppm P) over three years. Results showed that higher P uptake efficiency occurred at 1–5 ppm P compared to 15 ppm P. Phosphorus application levels were also reflected in the P concentrations of diagnostic leaves. Additionally, DNA extracted from the rhizosphere, and full-length 16S microbiome analysis, revealing significant correlations between P concentrations and shifts in microbial community composition at the genus level. These findings enhance our understanding of the interplay between phosphorus fertilization, root microbiomes, and nutrient uptake in table grapes, offering valuable insights for sustainable vineyard management.