Objective This study aimed to investigate the effects of different fertilization methods and fertilization ratios on the growth and fruiting indexes of the mother tree of P. chekiangensis and the physicochemical properties of the soil in the seed orchard, for optimizing the fertilization management of the seed orchard, and realizing the high and stable yield of P. chekiangensis. The results provide a scientific basis and technical support.

Method The first seed orchard of P. chekiangensis in China, located in Qingyuan Experimental Forestry Farm, Zhejiang Province, was used to investigate the effects of two fertilization methods (furrowing and spreading) and different ratios of nitrogen (0 g/plant for N₁, 400 g/plant for N₂, and 800 g/plant for N₃), phosphorus (0 g/plant for P₁, 300 g/plant for P₂, and 600 g/plant for P₃) and potassium (0 g/plant for K₁, 250 g/plant for K₂, and 500 g/plant for K₃) fertilizers on the fruiting traits and leaf nutrient elements of the mother trees of P. chekiangensis, as well as the soil physiochemistry of the seed orchard, so as to screen out the optimal fertilization methods and fertilization formulation.

Result Compared with the previous year, seed yield of P. chekiangensis under the furrowing and spreading treatments increased by 120.05% and 415.03%, respectively. Under the spreading treatment, the contents of alkaline hydrolysable nitrogen, available potassium and organic matter contents of the soil in the 0～20 cm layer and leaf total nitrogen content increased significantly by 34.54%, 19.47%, 41.89%, and 15.95%, respectively, compared with the control CK. Different formula fertilizations significantly increased the seed yield and quality of P. chekiangensis, with T5 (N₂P₂K₃) showing the largest increase compared with T1 (no fertilization). Under T5, fruit yield and 100-grain weight increased by 601.57% and 19.93%, respectively. In addition, T5 markedly increased soil available phosphorus and available potassium contents in the 0～20 cm layer by 248.03% and 157.62%, respectively, and increased available phosphorus and organic matter contents in the 20～40 cm layer by 146.42% and 21.99%, respectively. Leaf total nitrogen and total phosphorus contents increased by 9.49% and 53.76%, respectively.

Conclusion Based on comprehensive evaluation of seed yield, leaf nutrient elements and soil physicochemical properties, surface spreading was identified as the most effective fertilization method for promoting high and stable yield production of the mother tree of P. chekiangensis. The optimal fertilization regime was determined to be N₂P₂K₃.