Combined application of nitrogen and phosphorus promotes the nutrient element accumulation of Phoebe bournei container seedlings

Abstract

Phoebe bournei (Hemsl.) Yang, a valuable timber species, grows slowly in the seedling stage. In this experiment, the effects of the combined application of nitrogen and phosphorus on the biomass and nutrient status of P. bournei container seedlings were investigated. Using the exponential fertilization method, eight fertilization levels (CK, N1, N2, N3, P, N1P, N2P, and N3P) were set up for P. bournei one-year container seedlings. Following fertilization, the biomass and nutrient element contents of each organ of the seedlings were determined. The biomass, mass fractions of nitrogen, phosphorus, and potassium, as well as their accumulation and absorption in the organs of seedlings, were higher under various fertilization treatments than under CK. Additionally, when nitrogen and phosphorus were applied together, the organs of seedlings absorbed the most quantity of nitrogen, phosphorus, and potassium. The accumulation and distribution ratio of nitrogen, phosphorus, and potassium in the aboveground part of seedlings was higher than in the underground part. Furthermore, for nitrogen and potassium, fertilization treatments increased the distribution ratio in the underground part. All fertilizer treatments, except for the single P treatment, resulted in a decrease in the phosphorus allocation ratio in the underground part. Overall, fertilizer application can increase the nutrient element content of seedlings. The nutrient status of seedlings under the N2P treatment was better than other treatments, indicating that, with a synergistic effect of nitrogen and phosphorus, the N2P treatment could effectively promote the growth of P. bournei container seedlings.