合肥市绿地土壤氮磷有效性特点

以合肥市典型道路、公园和庭院绿地土壤为对象，测定分析了绿地土壤理化性状和氮磷有效性特点。结果表明，绿地表层土壤容重平均值为1．45g／cm^3，总孔隙度为43．6％；土壤电导率平均值为159μ S／cm；pH值多在7．5～8．5，碱性化明显。老城区土壤氮磷有效性显著高于政务新区，老城区表层土壤全氮和速效氮含量的平均值分别为1．38g／kg和4．52mg／kg，高出政务区18．9％和42．1％；全磷和速效磷分别为1009．3mg／kg和41．9mg／kg，分别是政务区的3．0和1．9倍。园林绿地土壤具明显的富磷特征。

Characteristics of Nitrogen and Phosphorus Availability of Urban Soils in Hefei

The characteristics of nitrogen and phosphorous availability of different urban soils, including streets, parks and courtyards, was investigated. The result from this study showed that the soil bulk density averaged 1.45 g/cm^3, and the mean total porosity was 43.6%. The mean value of EC was 159 /μS/cm. Most of the soils had pH values ranging from 7.5 to 8.5, indicating an obvious tendency to alkalinity. The mean concentrations of total N and available N were, respectively, 1.38 g/kg and 4.52 mg/kg for 0-10 cm soils in the old downtown area, which were 18.9% and 42. 1% greater than those in the newly-built district. The mean concentrations of total P and available P were, respectively, 1009.3 mg/kg and 41.9 mg/kg in 0- 10 cm soils in the old downtown area. which were 3.0 and 1.9 times as high as those in the newly-built district. The result suggests that the urban soils were rich in P.