Abstract:This study was carried out to investigate the changes of physicochemical properties of two bridge greening substrates and the effects on the growth and flowering of Bougainvillea ‘Royal Purple’ on Fuxin overpass in Futian District, Shenzhen City, China. The results showed that the pH, EC value and organic matter content of the two substrates were all decreased at the 18th month of planting, while the contents of alkali hydrolyzed N and available P were increased. The physicochemical properties except EC value of the two substrates still meet the requirements of planting soil of B. ‘Royal Purple’, and the available P content of substrate A was signifi cantly higher than that of substrate B (P<0.05), but there was no significant difference in other properties (P>0.05). The leaf SPAD value was decreased gradually with the increase of planting months, while the flower density at the 21st month of planting was significantly higher than those in other observation months (P<0.05). However, there was no significant difference in leaf SPAD value, nutrient contents or flower density between the two substrates (P<0.05). The results of correlation analysis showed that the flower density at the 18th month of planting was significantly positively correlated with the total K content in leaves (P<0.05), while the leaf SPAD value was significantly negatively correlated with the substrate available P content (P<0.05), and the significant negative correlation between leaf total N and matrix organic matter or alkali hydrolyzed N content was also observed (P<0.05).
