Effects of Pre-Hardening and Autumn Fertilization on Biomass Allocation and Root Morphology of Pinus koraiensis Seedlings

Abstract

The effects of pre-hardening fertilization and autumn fertilization on seedling growth have been studied separately, but studies on their combined effects are relatively scarce. We studied the effects of pre-hardening fertilization type and autumn fertilization level on biomass allocation and root morphology of container-grown seedlings of Korean pine (Pinus koraiensis Sieb. et Zucc.), a valuable evergreen conifer distributed from Changbai Mountain to the Xiaoxing’an Mountains in northeastern China. Three pre-hardening fertilization types (conventional fertilization, exponential fertilization, and controlled-release fertilizer) were all applied with 72 mg of nitrogen. We also applied four nitrogen levels of autumn fertilization: 0 mg/plant, 2 mg/plant, 4 mg/plant, and 6 mg/plant. We found that autumn fertilization increased Korean pine seedling biomass accumulation and root growth by 65.91%–92.15% and 108.86%–141.48%, respectively. There was significant interaction between pre-hardening fertilization type and autumn fertilization level on biomass allocation and root morphology. Seedlings with conventional fertilization during the growing season have the best response to autumn fertilization, particularly in the 2 mg/seedling and 4 mg/seedling treatments. Autumn fertilization can be applied to the cultivation of high-quality Korean pine seedlings.

Combined Application of Nitrogen and Phosphorus Promotes the Growth and Nutrient Accumulations of Cinnamomum camphora Container Seedlings

“…Biomass is considered an important indicator that reflects plant productivity, whereas nitrogen fertilizer affects biomass distribution in various parts of the plant [23]. Previous studies discovered that N fertilizer resulted in a significant improvement in the biomass content of the entire Pinus koraiensis seedlings [24] and in parts of the stems and leaves of Guindilia trinervis [25]. The findings of this research align with the above findings.…”

“…Root length, root surface area, root volume, and root average diameter play a decisive role in nutrient uptake. Accordingly, studying the morphological characteristics of the root system is extremely important [24]. Previous studies have shown that phosphorus plays an important role in lateral root morphology and root branching [26], affecting not only root development but also nutrient availability [27].…”