汉城湖绿化区土壤养分的分析与评价

采用野外调查及室内分析方法，对汉城湖12个绿化区域土壤养分进行了测定分析，并运用相关分析法和主成分分析法进行了综合评价，评价指标主要有pH、有机质、硝态氮、铵态氮、碱解氮、速效磷、速效钾、全氮、全磷、全钾。结果表明，1）有机质和氮素普遍缺乏；磷素偏低，钾素丰富；pH偏弱碱性；碱解氮、速效磷、速效钾等养分的空间分布很不均衡。2）在0~20 cm表层土壤中，属于高水平的样区有神明台区域和铜像区域，属于较高水平的样区有公司门口区域、五号桥区域、福迪汽贸区域、水车广场区域和四号桥区域，属于中等水平的样区有中兴阁区域、一号桥区域、围挡区域和榆园区域，属于较低水平的样区为三号桥区域；20~60 cm土层中，属于高水平的样区为神明台区域，属于较高水平的样区有铜像区域、福迪汽贸区域、水车广场区域、中兴阁区域、一号桥区域和三号桥区域，属于中等水平的样区有五号桥区域、榆园区域、公司门口区域、四号桥区域和围挡区域。3）除三号桥区域的0~20 cm表层土壤，其20~60 cm土层和其他11个区域的2层土壤养分综合指标值IFI值均>0.4，即达到中等水平及以上。

Measurement and Evaluation of Soil Nutrients in Gree Belts of Hancheng Lake

Methods of field survey and laboratory analysis were adopted to investigate the soil nutrients in the soil samples collected in 12 areas of the green spaces around Hancheng Lake of Xi’an. The overall nutritional situations were assessed by correlation and principal analysis methods. The evaluation indexes included pH, organic matter, nitrate nitrogen, ammonium nitrogen, alkali-hydrolysable nitrogen, available phosphorus, available potassium, total nitrogen, total phosphorus and total potassium. The results showed that, 1) The organic matter and nitrogen was generally inadequate; for macroelements, phosphorus was low, and potassium was rich; pH was in the range of weak alkaline; the spatial distributions of alkali-hydrolyzable nitrogen, available phosphorus, available potassium and other nutrient contents were not balanced. 2) In topsoil (0-20 cm), areas in which the highest levels of soil nutrients were found included Taiwan and Statue areas; high levels were in company gate, No. 5 bridge, Foday Qimao, water plaza and No. 4 bridge areas; middle levels were ZTE pavilion, No.1 bridge, Enclosure and Elm park areas; low levels were No. 3 bridge area. In 20-60 cm soil layer, Taiwan area was at the highest level; Statue, Foday Qimao, Water plaza, ZTE pavilion, No. 1 bridge and No. 3 bridge areas were at the high level; No. 5 bridge, Elm Park, Company gate, No. 4 bridge and Enclosure areas were at the middle level. 3) Except for the toptsoil (0-20 cm) of No. 3 bridge area, the values of IFI in other siols were more than 0.4, which reached the middle or above level.