Effect of nitrogen and phosphorus fertilization on biomass and nutrient distribution of Cunninghamia lanceolata seedlings

A pot experiment method was used to study the effects of different nitrogen and phosphorus fertilization on biomass and nutrient distribution of Cunninghamia lanceolata seedlings. The results show that the high phosphorus fertilization increases the biomass amounts of total plant and individual parts, and the plant biomass allocation ratios among leaves, stems and roots are also affected by different phosphorus fertilization. For treatment supplied with nitrogen and phosphorus, the biomass of leaves accounts for more than 45% of total plant biomass. Instead, applying nitrogenous fertilizer reduces the biomass amounts of leaves, stems and roots in Cunninghamia lanceolata. The application of nitrogen significantly increases N concentrations of roots and leaves, and remarkably decreases P concentrations of roots and leaves, but has no significant effect on nitrogen and phosphorus concentrations of stems. The application of phosphate fertilizer significantly decreases N concentrations of leaves, stems and roots. P concentrations of leaves, stems and roots are increased with the increase of phosphorus fertilization supply. Nitrogen mixed with phosphorus fertilization can significantly affect N and P concentrations, and N and P accumulations of leaves, stems and roots. Leaves are the main tissue for nitrogen and phosphorus accumulation in the plant. High nitrogen or phosphorus levels on Cunninghamia lanceolata decrease P or N nutrient use efficiencies, increase N or P nutrient use efficiencies. Different nitrogen and phosphorus fertilization ratios on Cunninghamia lanceolata significantly influence N/P ratios of leaves, stems and roots. This research results indicate that the nitrogen and phosphorus fertilization increases biomass and N and P concentrations in leaves, stems and roots of Cunninghamia lanceolata seedlings, and affects nutrient distribution and nutrient balance of total plant.