Seasonal dynamic characteristics and nutrient elements correlations in Illicium verum leaves.

[Objective]The seasonal dynamic characteristics and the correlations between N, P, K, Ca, Mg, Cu, Zn, Fe, Mn, and B elements in mature Illicium verum leaves were studied in order to provide theoretic foundation for achieving timely fertilizer application, suitable fertilizer type, and appropriate fertilization concentration in Illicium verum cultivation. [Method]Using the normally grown 15-year old mature Illicium verum forest as investigation subject, samples were collected 1 time around every 60 days to determine the nutrient element content in mature leaves, analyze the seasonal dynamics characteristics, and evaluate the correlations between the elements. [Result]Large and medium amounts of nutrient element contents in mature leaves of Illicium verum were arranged in the following order: NKCaMgP, while the content of trace elements were arranged in the following order: MnFeBZnCu. The nutrient element content in leaves fluctuated according to seasonal changes. For large and medium amounts of elements, the fluctuation was small, but in trace elements, the fluctuation was noticeable large. P, Ca, Cu, Zn, B, and other nutrient elements were consumed along with plant growth, which caused the element contents in mature leaves to decrease. [Conclusion]There were certain seasonal dynamic changing rules of the nutrient element content in Illicium verum leaves. During the exuberant growth season, the elements consumption increased sharply due to the nutrient necessity in plant reproductive organs and new tip leaves, which lead to the decline of some nutrient element contents in mature leaves. Fertilization should be applied during early growth stages before the exuberant growth period, and at the same time, the amount of every nutrient elements should be coordinated in order to avoid excessive antagonistic actions between the elements.