Effects of Substrate Compositions on the Growth and Photosynthesis Characteristic of Tilia miqueliana Container Seedlings

In order to explore the effects of different substrate compositions on the growth and development of Tilia miqueliana container seedlings, and selected the suitable substrate composition, the study set up 4 kinds of mixed substrates consisting of peat, poplar skin, organic fertilizer and perlite in proportions of 3∶0∶1∶1, 2∶1∶1∶1, 1∶2∶1∶1 and 3∶3∶2∶2(respectively named as G₁, G₂, G₃, G₄), and compared the morphological and photosynthesis indexes of T. miqueliana container seedlings cultivated in different substrate. The results showed that there are significant differences in physical and chemical properties among different substrate composition. G₁ is significantly lower than G₃, while the nitrogen and phosphorus concentrate are significantly higher than G₃. Substrate composition playes a significant role in the growing and development of T. miqueliana container seedlings and the promotive effect on it performs as G₁ > G₂ > G₄ > G₃. With the increase of percentage of peat matrix, the container seedlings of T. miqueliana grow better. The seedlings height and diameter of G₁ are 33.73 cm and 7.96 mm, which are significantly higher than G₃. The total fresh weight of roots and stems of G₁ seedling are 14.22 g/plant and 5.54 g/plant, which are significantly higher than other treatments. The total root volume of G₁ seedlings is 13.6 cm³ and the number of primary lateral roots is 17.6, which are significantly higher than G₃. The gross chlorophyll content and photosynthetic rate of G₁ seedlings are 2.96 mg/g and 5.06 μmol/(m²·s), which are significantly higher than G₃. Given the seedlings growth synthetically and various indexes, G₁ is the suitable composition in the cultivation of 1-year-old T. miqueliana container seedlings.