Research on fertilization formula for seedlings of rare species Ormosia hosiei

This study aimed to investigate the impact of nitrogen (N), phosphorus (P), and potassium (K) elements on the early-stage growth of Ormosia hosiei saplings during afforestation and identify the optimal fertilization formula for enhancing their growth.

2 a O. hosiei saplings were selected as the material, and a large container was used to simulate the afforestation habitat. The “3414” incomplete block orthogonal design was employed to fertilize nitrogen, phosphorus, and potassium. The fertilizers used were urea, superphosphate, and potassium chloride, with their active components being N (46%), P₂O₅ (22.6%), and K₂O (52.1%), respectively. The height, ground diameter, root system, and biomass of O. hosiei saplings were measured under different nitrogen, phosphorus, and potassium treatments.

The rational application of N, P, and K elements significantly promoted the growth of O.hosiei saplings. Among the 14 treatments, the O. hosiei saplings treated with T7 (N2P3K2) exhibited the most favorable growth response. Compared to the control, the seedling height increment, ground diameter increment, and total biomass increased by 148.64%,117.20%, and 87.80%, respectively, with the root development being the most robust. The effects of the three elements, under each treatment, followed the order of P > N > K, highlighting the importance of phosphate fertilizer for O. hosiei growth. Different equations were derived to represent the individual, binary, and ternary effects of biomass and nitrogen, phosphorus, and potassium fertilization. The results showed a decreasing trend in the application effect of nitrogen, phosphorus, and potassium, with the highest interaction effect observed for NP fertilizer. Furthermore, the combined application of all three elements yielded significantly better results than any two-element combinations. The membership function analysis identified T7 as the optimal fertilization treatment group.

The treatment of T7 (N2P3K2) can significantly improve the height, diameter, root, and total biomass of 2 a O. hosiei seedlings. The fertilization model showed that the best fertilization formula was recommended by N 42.917 g, P₂O₅ 70.565 g, and K₂O 24.439 g for each O. hosiei eedling, with an appropriate fertilization ratio of nitrogen, phosphorus, and potassium at 1:1.64:0.56.