重庆主城区市街绿地土壤肥力质量评价及管理对策

Assessment of Soil Fertility Quality for Urban Green Spaces in Chongqing City and Measures for Their Management

近年来，由于人为活动的强烈影响，城市绿地土壤性质发生了显著的改变，从而影响了绿化植物的正常生长，降低了城市绿化质量．通过对重庆市主城六区的市街绿地土壤的质地、容重、pH、有机质、碱解氮、有效磷、速效钾等物理化学性质的研究，对市街绿地土壤质量进行了综合评价．结果表明，重庆市街绿地土壤总体质量不高，具体表现为：土壤石砾含量高，混有大量建筑废弃物；土壤pH值较自然土壤明显增高，碱性土壤占73．4％；有机质含量在4．84～52．9g／kg之间，处于中等偏低水平；土壤碱解氮含量处于15．0～183mg／kg之间，含量水平较低；有效磷含量在1．00-81．5mg／kg之间，61．06％的土壤有效磷含量较低；速效钾含量适中，在41．0～499mg／kg之间；土壤EC值升高，53．2％的土壤即将或已经发生盐渍化；绝大部分土壤容重适中，可以满足植物生长．根据重庆市街绿地土壤质量状况，提出了加强重庆市街绿地土壤科学管理的措施和建议．

In recent years, the characteristics of urban green space soil have changed a lot because of human activities. These changes influence plant growth and lower the quality of urban afforesting and greeni In a study reported in this paper, soil samples of road greenbelts, street green spaces and green spaces ng. affiliated to various institutions in the urban area of Chongqing were collected and their texture, bulk densi ty, pH, organic matter, and available N, P, K were studied. The results indicated that the soil fertility quality was not high. many soils were mixed with much construction waste, which caused a high gravel content level; 73.4% of the soil samples were alkali soil, which indicated that soil pH had obviously risen compared with the natural soil; organic matter content was at a slightly low level, ranging from 4. 84 to 52.9 g · kg^-1 available N and P were low, especially the latter available N content varied from 15.0 to 183 g · kg^-1 while available P varied from 1.00 to 81.5 g · kg^-1 available K content was at a moderate level, 53.2% which between 41.0 and 499 g · kg^-1. EC was significantly higher than that of the natural soil, and of the soils samples showed, to different extents, salinization. Their bulk density was moderate, could meet the requirements of the plants. According to the results of the investigation, some meas ures and suggestions were put forward for the scientific management of the soil of urban green spaces.