Abstract: We explored the variations of seedling height and ground diameter growth rhythm and biomass of Brachychiton acerifolius, Koelreuteria bipinnata and Heteropanax fragrans on municipal sewage sludge, aiming to provide reference for the resource utilization of sewage sludge in landscape greening. In a 1-year pot experiment, we measured height and ground diameter of seedlings of the three species planting on red soil (CK), sludge-red soil substrate (mass ratio 50%, S50), and 100% sludge (S100). Logistic equation was used to establish the model of plant growth. Growth rhythm and biomass of three species on different substrates were comparatively analyzed. The results showed that: (1) Compared with CK, S50 and S100 significantly increased height of B. acerifolius, height and ground diameter of K. bipinnata, and ground diameter of H. fragrans. S50 and S100 also increased maximum monthly growth and total increment of height and ground diameter of H. fragrans. The maximum monthly growth of height and ground diameter of K. bipinnata was lower than that of B. acerifolius and H. fragrans. (2) The Logistic growth model fitting effect of height and ground diameter reached extremely significant level (P<0.01). The growth phases of plant height and ground diameter were divided into early growth phase, rapid growth phase, and late growth phase. (3) Root biomass, stem biomass, leaf biomass and quality index of H. fragrans were higher in S50 and S100 than in CK. H. fragrans had the highest quality index (14.20) in S50 among the three species, and the quality index of H. fragrans and B. acerifolius in S100 treatment was significantly higher than that of K. bipinnata. According to the growth performance, H. fragrans had the best sludge adaptability, followed by B. acerifolius and K. bipinnata. The Logistic growth model could better predict and analyze the growth pattern at seedling stage, which reflected the growth response of different plant species to sewage sludge.

Key words: substrate, growth rhythm, woody plant, sewage sludge resource utilization