Abstract: [Objective] Nitrogen(N) supply and container type have each proved to effectively regulate seedling quality. In this study, we tested if the combination of the two approaches couldimprove seedling quality and produce a superposition effect on seedling growthin order to provide a theoretical basis in the containerized seedling cultivation.[Method] Quercus variabilis, with a dominant taproot, was reared in two different depth containers(25 cm, 36 cm) with application of either deficient(25 mgN·seedling^-1) or luxury(100 mgN·seedling^-1) nitrogen supply, in a two factors completely randomize design. Seedling growth, root characteristics, and nutrient concentration were measured at the end of the growth season.[Result] N supply and container depth were significantly interacted on root N concentration, root volume, andsurface area for medium-class roots(2.0[Conclusion] Both the interactive and main effects of N supply and container depth indicated the necessity of combining the two approaches to improve seedling quality. The optimum combination of 100 mgN and 36 cm container was recommended for the container seedling production of this species with a dominant taproot.

Key words: container seedling, nitrogen supply, container depth, root architecture, seedling growth, nutrient concentration