Effects of shading and fertilization on growth and nitrogen accumulation of Phoebe zhennan seedlings

Objective  This study aims to reveal the effects of shading and fertilization on growth and nitrogen accumulation of Phoebe zhennan seedlings to provide scientific basis for the growth control of this plant. Method  The two-split-plot test design was used to analyze the effects of shading, fertilization, and interaction of shading and fertilization on the growth, biomass accumulation and nitrogen accumulation of the 1-year-old P. Zhennan seedlings. The main plot contained three different shading levels: natural light (A1, 0% of shading rate), one-layer shading (A2, 54.5% of shading rate), and two-layer shading (A3, 85.3% of shading rate). Each main plot contained three different sub-plots with three different fertilization levels: no fertilization (B1), mild fertilization (B2, 3.3 g compound fertilizer per plant), and moderate fertilization (B3, 6.7 g compound fertilizer per plant). A total of 9 treatments were included in this study. Result  The growth and nitrogen accumulation were significantly influenced by shading, fertilization, and their interaction (P＜0.05). The seedling height, basal diameter, and biomass accumulation under A2B2 treatment were 77.2%, 30.3% and 62.1% higher than those under other treatments, respectively. Furthermore, the nitrogen accumulation reached the maximum under A2B2 treatment, 68.3% higher than that of other treatments. However, the nitrogen content was highest under A3B3 treatment, and was significantly higher than that under other treatments (P＜0.05). Conclusion  Moderate shading and fertilization can increase the nitrogen accumulation, and promote the photosynthesis, growth and biomass accumulation of P. Zhennan, but excessive shading and fertilization can inhibit its growth to some extent. [Ch, 3 fig. 4 tab. 24 ref.]