Intensive management of phosphorus fertilization in Camellia oleifera Abel. to minimize phosphorus losses to the environment

Camellia (Camellia oleifera Abel.) plantation often needs fertilizer application to ensure fruit yield, and camellia fruit yield might be affected by soil phosphorus supply and microbial community and function. However, a large fraction of applied phosphorus is lost through leaching and runoff, which may cause eutrophication risks in waterbodies. Intensive management of phosphorus fertilization based on the comprehensive balance among fruit yield, soil nutrient and microbial property is required to quantify appropriate phosphorus fertilization rate. In this study, a camellia plantation located in southern China was selected, and four different fertilization treatments were established: control without P fertilizer (P0); 114.5 kg phosphorus pentoxide ha−1 applied as sodium dihydrogen phosphate (P1); 229.0 kg phosphorus pentoxide ha−1 (P2) and 343.5 kg phosphorus pentoxide ha−1 (P3). The fruit yields of P1, P2 and P3 treatments were approximately 1.5, 2.0 and 2.0 times of that measured from the P0 treatment, respectively. Bacterial community richness estimators and diversity indices in the P2 treatment were significantly higher than those in the P3 treatment. Relative abundances of Bacteroidetes, Planctomycetes, Verrucomicrobia and Eremiobacterota were significantly affected by the phosphorus fertilization. The gram-negative bacterial relative abundance was significantly lower in the P3 treatment than in the other treatments. Relative to the P2 treatment, the P3 treatment had significant decreases in soil pH, bacterial community diversity and gram-negative bacterial relative abundance, which might offset the stimulation of higher phosphorus supply for fruit yield. Based on the comprehensive balance among fruit yield, fertilization input cost, soil environment impact and microbial property, 229.0 kg phosphorus pentoxide ha-1 fertilization is appropriate for this camellia plantation. Future phosphorus fertilization in the camellia plantation should consider the comprehensive balance among yields, soils and microbial properties.