Selection of Formula of Light Substrates for Container Seedlings of Cunninghamia lanceolata and Pinus elliottii

Seven different formula of substrates for seedling cultivation of Cunninghamia lanceolata and Pinus elliottii were prepared with peat, vermiculite, perlite, fermented dairy manure, fermented pine bark, fermented wood chips, and rice hull. 4 kg controlled release fertilizer with 18% of N, 6% of P2O5 and 12% of K2O was mixed in each cubic meter of substrate. On 16th December 2020, seeds of C. lanceolata and P. elliottii were sowed in plug. On 15th April 2021, seedlings were transplanted in 7 substrates. On 20th December 2021, investigations were carried out on ground diameter, seedling height and survival rate. The results showed that different substrates had significant effect on the growth and quality of container seedlings. The experiment resulted the optimal formula for cultivation of container C. lanceolata and P. elliottii seedlings was as follows: peat: perlite: fermented dairy manure: fermented wood chips: fermented pine bark=0.3:0.1:0.2:0.15:0.25. There was no significant difference in seedling growth and survival rate between the selected formula and the traditional formula (peat: vermiculite: perlite = 0.4:0.3:0.3), but the cost of the selected formula was reduced by 25%.