Soil Nutrient Characteristics And Heavy Metal Pollution Assessment Of Typical Park Green Spaces In Beijing

In order to understand the soil fertility and heavy metal pollution in Beijing park green space,and to provide theoretical basis and reasonable suggestions for urban greening management and residents' health,this paper takes 10 representative park green soils in Beijing as the research object,and the royal garden and The soil nutrient levels of modern garden greenbelts were statistically analyzed.The soil environmental quality of the royal gardens and modern garden greenbelts was evaluated by the ground accumulation index,Nemero index and potential ecological hazard index.The main results are as follows:(1)The average soil pH values of Beijing Royal Garden and Modern Garden Greenland belong to neutral soil.The average content of organic matter is 30.91 and 22.87g/kg,respectively.The average content of alkali nitrogen is 89.13 and 63.89mg/kg,respectively.The contents were 93.26 and 87.40 mg/kg,respectively.The average content of available potassium was 218.22 and 242.24 mg/kg,respectively.T-test was carried out on the fertility indexes of the royal garden and modern garden green soil in the study area.The results showed that in addition to available phosphorus and available potassium In addition,pH,organic matter,and alkali nitrogen all reached significant differences.(2)The average contents of heavy metals Cu,Zn,Cd,Pb,As,Hg,Cr and Ni in the garden green space of Beijing are 47.83,98.04,0.27,64.78,8.53,6.85,52.83 and 24.65 mg/kg,respectively.The average contents of heavy metals in the middle were 27.41,71.09,0.24,22.86,7.48,0.66,51.18 and 25.18 mg/kg.One-way analysis of variance of heavy metals in two types of parks showed significant differences in heavy metals Cd,Pb,Hg and Cr.There were no significant differences in the remaining heavy metals.(3)When the soil background value of Beijing and the soil background value of China are used as reference values,the accumulation of eight heavy metal elements in the soil of the royal garden greenland is higher than that of modern gardens,especially the heavy metal Hg,which is a heavy accumulation,and the remaining heavy metals are slightly accumulated;When the soil background value of Beijing and the national soil environmental quality standard are the reference values,the royal garden pollution level is higher than that of modern gardens.The potential ecological risk coefficient indicates that the royal garden is a strong ecological risk,and the modern garden is a medium ecological risk;When the secondary standard of soil environmental quality is the reference value,the degree of pollution of the royal garden is higher than that of the modern garden.The potential ecological risk of the royal garden is a strong ecological risk,and the modern garden is a slight ecological risk.(4)Correlation analysis of soil fertility indexes of Beijing royal gardens and modern garden greenbelts shows that in the soil of royal garden greenland,alkali nitrogen and available phosphorus are significantly correlated with organic matter and pH,and between alkaline nitrogen,available phosphorus and available potassium.There is significant correlation between the two;in the modern garden green soil,organic matter is significantly correlated with alkali nitrogen,available phosphorus and available potassium,and alkali nitrogen is significantly correlated with available phosphorus.Using correlation to analyze the heavy metal elements in soil,it can be seen that in the royal garden,Cu is significantly correlated with Zn,Pb and Hg,and Hg is significantly correlated with Pb and As.In modern gardens,Cu is significantly correlated with Zn,Cd and Pb,Zn and Cd.Hg and Ni are significantly correlated,and Cd is significantly correlated with As.According to the significant correlation of heavy metal elements,it is suggested that they may have the same source.In short,the soil fertility level of modern garden green space is lower than that of royal gardens.The heavy metal pollution of royal gardens is higher than that of modern gardens,especially the heavy metal Hg pollution.Therefore,Beijing should focus on strengthening the fertility status of modern gardens and the royal Pollution prevention and treatment of heavy metals in gardens,especially heavy metal elements Hg.