Abstract: The soil physiochemical properties, such as pH, organic matter and available nutrients were determined. And soil improvement of road greening in Nanning, comprehensive soil fertility was evaluated by the Nemorow grading method. The results indicated that the texture types mainly included loam and viscous loam soil. The soil pH was dominated by neutrality（pH 6.5~7.5）. The average of soil bulk density was 1.14 g/cm³, CEC （cation exchange capacity） was 12.72 cmol（+）/kg. Organic matter and available nitrogen were distributed in grades 1 to 4 with an average of 31.54 g/kg and 110.24 mg/kg. Available phosphorus was above grade 2 or higher （high level） with an average of 43.4 mg/kg. All the available potassium （mean 59.21 mg/kg） were at the level of grade 4 and below medium content. Nemerow comprehensive fertility index analysis showed that the soil fertility index of newly-built green land in Nanning was between 1.19~1.78, which was in the middle and upper level. It was suggested to pay attention to the supply of natural organic matter in greenbelt soil and promote the benign cycle of urban soil ecosystem.

Key words: urban green space, soil quality, evaluation, Nanning city