广州市花都城区绿地土壤肥力与重金属污染分析

在对广州市花都城区绿地土壤取样调查的基础上，采用全国第二次土壤普查养分分级标准和内梅罗污染指数法等对其土壤肥力和重金属污染情况进行分析评价，揭示花都城区绿地土壤存在的问题。结果表明，花都城区绿地土壤容重变幅在1.25～1.75 g·cm–3之间，孔隙度变幅在30.81%～47.42%之间，pH在6.16～7.68之间，有机质含量在四级及以下标准，严重缺乏氮素和磷素。不同绿地类型中，厂区路旁绿地土壤重金属污染最严重，其次为主干道两侧绿地；研究区As污染最严重，Pb次之，未受Zn污染，存在不同程度的Cu、Cd、Cr、Ni、Hg污染。相关性分析表明，土壤pH与全钾、碱解氮含量极显著相关，有机质与全氮极显著相关，全氮、全磷分别与碱解氮、有效磷显著正相关，全钾与碱解氮显著负相关；重金属元素中，Cu与Zn、Cr、Ni极显著相关，Zn与Cu、Pb、Cd、Cr、Ni极显著相关，Pb与Zn、Cd极显著相关，Cr与Cu、Zn、Ni极显著相关，As和Hg与其他重金属元素均无显著相关性。

Analysis of Soil Fertility and Heavy Metal Pollution of Urban Green Space in Huadu,Guangzhou

Based on the investigation of soil samples of urban green space in Huadu district of Guangzhou, the soil fertility and heavy metal pollution were analyzed and evaluated by using the nutrient grading standard of the second National Soil Census and Nemerow pollution index method. The results showed that the soil bulk density of green space in Huadu urban ranged from 1.25 g·cm–3 to 1.75 g·cm–3. The range of porosity was 30.81%–47.42%, and the pH was from 6.16 to 7.68. The contents of organic matter were below grade 4, and nitrogen and phosphorus were seriously deficient. In different types of green space, the heavy metal pollution of roadside green space soil was the most serious, followed by the green space on both sides of the main road; the pollution of As was the most serious in the study area, followed by Pb, not polluted by Zn, and Cu、Cd、Cr、Ni、Hg had different degrees of pollution. Correlation analysis showed that soil pH was significantly correlated with total potassium and alkali hydrolyzable nitrogen. Organic matter was significantly correlated with total nitrogen. Total nitrogen and total phosphorus were significantly positively correlated with alkali hydrolyzable nitrogen and available phosphorus, respectively. And total potassium was significantly negatively correlated with alkali hydrolyzable nitrogen. Among heavy metal elements, Cu was significantly correlated with Zn, Cr and Ni; Zn was significantly correlated with Cu, Pb, Cd, Cr and Ni; Pb was significantly correlated with Zn and Cd; and Cr was significantly correlated with Cu, Zn, Ni. As and Hg had no significant correlation with other heavy metals.