root metagenome Targeted Locus (Loci)

Phosphorus deficiency limits maize production in karst rocky desertification regions. We conducted a field experiment with four phosphorus application rates (P0: 0, P1: 75, P2: 150, P3: 225 kg ha-1) and profiled nutrient allocation and root endophytic bacterial communities at the jointing and milk-ripening stages. Moderate phosphorus input (150 kg ha-1) maximized nutrient uptake, whereas high phosphorus tended to suppress phosphorus accumulation. Increasing phosphorus reduced bacterial diversity but increased the relative abundance of Proteobacteria and Actinobacteria. Community shifts were associated with phosphorus availability, with high phosphorus enriching taxa such as Pseudomonadaceae. These data support optimization of phosphorus fertilization for maize in karst regions.