Abstract

This study investigated the impact of various nitrogen forms on American ginseng (Panax quinquefolius) seedling growth. Thirteen treatments of inorganic and organic nitrogen combinations were tested in the first year and growth indicators were measured. In the second year, treatments with significant growth promotion effects were further verified. The results showed improved growth of American ginseng seedlings when the concentrations of nitrate and ammonium nitrogen were 1.5 and 0.5 mM, respectively. The addition of 0.5 mM tyrosine and 0.1 mM glycine as organic nitrogen to this combination of high nitrate and low ammonium further improved seedling performance. However, American ginseng seedlings treated with high ammonium (1.5 mM) and low nitrate (0.5 mM) concentrations combined with organic nitrogen did not exhibit any growth-beneficial responses and showed a negative response at high organic nitrogen doses. This study suggests that American ginseng is a nitrate-loving plant and that the combination of higher nitrate with lower ammonium nitrogen concentrations, added with an appropriate amount of organic nitrogen, may greatly promote seedling growth. These results may be beneficial for implementing management strategies to effectively overcome the challenges encountered by attempts to continuously crop American ginseng with success.

Key words: Panax quinquefolium; inorganic nitrogen, organic nitrogen, continuous cropping, seedling growth, nitrate, ammonium, survival rate.