湖南省主要城市园林绿地土壤养分评价

为了对湖南省主要城市园林绿地的土壤养分进行评价，笔者根据湖南省主要城市地形，对6个丘陵城市（湘潭，株洲，衡阳，郴州，娄底，邵阳）、4个山地城市（怀化，吉首，张家界，永州）和4个平原城市（常德，益阳，岳阳，长沙）园林绿地土壤进行采样，每个城市又按公园绿地、行政事业单位（包括学校、医院、政府机关）、住宅区和主干道分别取样。结果表明：（1）湖南省主要城市园林绿地土壤pH较高，均值为7.9，土壤有机质(SOM)较低(6.8 g/kg)，铵态氮(NH₄⁺-N)、硝态氮(NO₃^--N)处于较低水平，速效磷(AP)、速效钾(AK)、速效钙(ACa)、速效镁(AMg)处于较高水平，速效硫(AS)、速效铁(AFe)、速效铜(ACu)、速效锰(AMn)、速效锌(AZn)和速效硼(AB)的含量适中；（2）土地利用方式对平原城市土壤养分含量影响显著，住宅区绿地土壤pH显著高于事业单位、公园和主干道，公园绿地的AS、ACu、AZn和AMn显著低于其他3种土地利用方式；（3）不同地形城市土壤养分含量存在显著差异，丘陵城市和山地城市的pH显著高于平原城市，山地城市的SOM、AK、AMg、NH₄⁺-N、ACu、ACa和AMn显著低于丘陵城市和平原城市，丘陵城市的AP和AB显著高于山地城市和平原城市，平原城市的AS和AFe显著高于丘陵城市和山地城市。研究结果对于构建湖南省主要城市园林绿化体系具有理论和实践意义。

Assessment of Soil Nutrient in Urban Greens in Main Cities of Hunan Province

In order to assess the soil nutrient in urban garden greens of main cities in Hunan Province, according to the topography of those cities, soil samples were collected from 6 hilly cities (Xiangtan, Zhuzhou, Hengyang, Chenzhou, Loudi and Shaoyang), 4 mountainous cities (Huaihua, Jishou, Zhangjiajie and Yongzhou), and 4 plain cities (Changde, Yiyang, Yueyang and Changsha). Soil of each city sampled according to 4 different land-used types, including park, administrative institution (school, hospital and government institution), residential area and arterial road. The results showed that: (1) the pH of garden greens in main cities were relatively high, with the average value of 7.9, while the contents of SOM were relatively low (6.8 g/kg), the contents of NH₄ -N and NO₃^--N were low, AP (Available P), AK (Available K), ACa (Available Ca) and AMg (Available Mg) were at higher levels, AS (Available S), AFe (Available Fe), ACu (Available Cu), AMn (Available Mn), AZn (Available Zn) and AB (Available B) had moderate contents; (2) land-use types significantly affected soil nutrient contents in plain cities, the soil pH of greens in residential area was significantly higher than that in administrative institution, park and arterial road, the soil contents of AS, ACu, AZn and AMn in park greens were significantly lower than that in the other 3 land-use types; (3) soil nutrient contents had significant differences among different topographies, the soil pH in mountainous and hilly cities were significantly higher than that in plain cities, the contents of SOM, AK, AMg, NH₄ -N, ACu, ACa and AMn in mountainous cities were significantly lower than that in hilly and plain cities, the contents of AP and AB in hilly cities were significantly higher than that in mountainous and plain cities, the contents of AS and AFe in plain cities were significantly higher than that in hilly and mountainous cities. All the results could provide theoretical and practical significance for the construction of landscape green system.