Effects of Container Size, Substrate Composition and Controlled-Release Fertilizer Dosage on the Growth and Quality of Castanea henryi Container Seedlings

Objective To investigate the effects of container size, substrate composition, and controlled-release fertilizer dosage on the growth and quality of Castanea henryi container seedlings, providing theoretical support and practical guidance for cultivating high-quality seedlings.

Methods The experiment adopted an orthogonal design, with three main variables: substrate composition（A）, container size（B）, and controlled-release fertilizer dosag（C）e. Sixteen treatments were set up, and seedling height, ground diameter and biomass of one-year-old C.henryi container seedlings under all treatments were measured,with the height-diameter ratio calculated. Membership function analysis was used for comprehensive evaluation.

Results Substrate composition（A）、 controlled-release fertilizer dosage（C） and the interaction between them （A × C）significantly affected the growth of C.henryi container seedlings, whereas container size had no significant effec. The treatments with the highest membership function values for seedling height and ground diameter were A₃B₁C₂ and A₂B₁C₃. Considering cost and seedling growth, the most suitable treatment for container seedling cultivation was A₃B₁C₂.

Conclusion Comprehensive analysis suggests that the optimal combination for cultivating C.henryi container seedlings involves using 6cm × 8cm non-woven nursery bags as containers, a substrate mix of coconut coir: peat: yellow soil at a volumetric ratio of 1:2:1, and adding controlled-release fertilizer at 3 kg/m³. This combination can produce one-year-old container seedlings above 60 cm in height. This study provides a scientific basis for the efficient cultivation of C.henryi container seedlings.