深圳城市绿地土壤肥力质量评价及管理对策

城市绿地是城市生态系统的重要组成部分,被称为城市的"肺"。城市绿地土壤通过其支持的植物、微生物和自身的功能,美化和净化城市环境,对城市的可持续发展具有重要意义。采集深圳市中心城区主要公园绿地、道路绿化带、住宅区绿地和单位附属绿地0～20cm,20～40cm土壤,研究了土壤质地、容重、孔隙度、阳离子交换量、pH、有机质、氮、磷、钾等物理化学性质。结果表明,深圳城市绿地土壤以砂壤和轻壤土为主,20～40cm土壤中松砂和紧砂土占有一定比例,土壤砾石含量高,重砾质土壤占91%以上;表层土壤(0～20cm)容重大,孔隙度小,阳离子交换量低;土壤pH较自然土壤明显增高,以中性和微酸性为主。土壤有机质处于较低的水平;全氮、碱解氮和全磷处于很低水平,有效磷处于中等水平;土壤全钾、速效钾处于中等或以上水平。0～20cm土壤中有机质、全氮、碱解氮显著高于20～40cm土壤。根据深圳城市绿地土壤质量状况,提出了加强深圳城市绿地土壤科学管理的措施和建议。

Soil Fertility Quality Assessment and Managing Measures for Urban Green Space in Shenzhen City

Urban green space is a very important part of urban ecosystem, and usually called as urban "lung". Through the functions of its supporting plants and microorganisms and itself, the soil of urban green space can beautify and clean urban environment, and has great significance for urban sustainability. Soil samples with 0~20 cm and 20~40 cm depths of park green space, road greenbelt, residential area and green space affiliated to units were collected at central district in Shenzhen city, and soil texture, bulk density, porosity, CEC, pH, organic matter, N, P, K were studied in this paper. The results indicated that the soil texture was dominated by sandy loam and light loam, the soil texture for 20~40 cm depth was accounted for loose sand and tight sand to a certain degree. Gravel content was high in soil, heavily gravelly soils account for more then 91%. Surface soil (0~20 cm) had a high bulk density, low porosity, and low CEC. The pH value of urban green space soils in Shenzhen city were distinctly high as compared with natural soils, and dominated by neutrality and slightly acid. soil organic matter was low, total N, alkali-hydrolyzable N and total P, was very low, soil available P, total K and available K was medium or over medium. Organic matter, total N and alkali-hydrolyzable N in soils with 0~20 cm depth were much higher than those with 20~40 cm depth. According soil quality situation of urban green space in Shenzhen city, some measures and suggestions were put forward for soil scientific management.