Study Of Dahuashan Geochemical Characteristics Of Soil In Beijing District Of Pinggu City

Pinggu district is located in the northeast of Beijing City, 70 kilometers away from Beijing City, known as the "hometown of big peach", it is an important production base in Beijing City, is the first area of the country’s big peach production. The main study area Dahua town is located in Pinggu District in the northwest, north of Miyun County handover, 1997, the Beijing municipal government life as the suburbs of big peach first town ", peach has become the town’s main economic crop. This study mainly in Pinggu District Dahua town and surrounding ecological environmental geological and geochemical background of geochemical survey and topsoil samples were collected, in the division of the terraces of the study area based on and analysis of the geochemical characteristics of soil elements, and geochemical evaluation of soil quality, provide scientific and reasonable suggestions for the peach cultivation and agricultural production. In this paper, the following results are obtained:1. The study area soil oxidation in the surface layer of CaO、K₂O、Org accounted for surface soil chemical component proportion is the largest, followed by the three elements of N、P、Mnand other trace elements accounted for a smaller proportion. The background values of surface soil elements in the study area were compared with the background values of Chinese soil elements, the enrichment coefficient of most elements was greater than 1, and the enrichment coefficient of P was 2.18. The background values of the surface soil elements in the study area were similar to that of the soil elements in Beijing City, the background values of most elements were close, and the enrichment coefficient of Cd was 2.41.2. of the study area is the main type of terrace terrace, there are some two grade and three grade terraces. Terrace, the second terrace and third level terrace soils of most elements in the content and the background values close to, only the second terrace are a few kinds of element enrichment coefficient is larger. Mean per Mn terraces are higher than the background value and Mo is closest to the elements and the background values; three Terrace Soil pH value was less than 6.5, think of the soil is acidic.3. According to the pH of the soil in the study area of soil elements analysis, acidic, neutral and alkaline soil element enrichment coefficient and were 20.31, 28.40 and 21.07, it is concluded that the most abundant element content of soil neutral and acidic and alkaline soil elements enrichment coefficient is close to. K₂O and N have little enrichment coefficient in different acidity in the soil, that has little effect on the content of K₂O and N in soil by acid alkali.4. The surface soil samples of beneficial and harmful element classification analysis, rich content of beneficial elements of P、K₂O、Mo、Cu、Mn and Se. Comparison of the content of the lack of elements of the N and Org, alkali solution ratio of nitrogen, available phosphorus, available potassium, B and Zn rich are accounted for more than 70%, but there are also some areas lack, of which there are two soil Cu and Zn content exceeds the upper limit value. The mean value Chinese compared with the soil background values of heavy metals in soils in the background, most of heavy metals enrichment coefficient is greater than 1, only Hg enrichment coefficient is less than 1 to 0.68. From the coefficient of variation of heavy metal elements, only Cd and Ar coefficient of variation were 0.85 and 0.78, indicating that cadmium and arsenic content in the soil of the study area distribution may not uniform.5 through the N, P, K₂O and organic geochemical evaluation of single index, P and K₂O are generally rich in content in the study area, N and lack of organic matter. Through analysis of Cr、Ni、Cd、Pb、Ar、Hg、Cu、Zn heavy metal elements, it is found that the Southwest（belonging to Liu Jia Dian town region） exist more serious of Cd, Pb and as in three kinds of heavy metal elements pollution. Based on hierarchical analysis method of soil nutrients and the environment of comprehensive evaluation, the results show that, the soil nutrients in the study area which belongs to medium level, most of the regional soil environment clean, in the southwest Liu shop around and Wan Zhuang surrounding soil environment pollution is serious.Overall, the study area of soil nutrients is more abundant, there is only a few elements lack soil environment is clean, only Liu Jia Dian Zhen in the vicinity of the region by the pollution of heavy metals. Most of the study area was consistent with the basic requirements of produce of social effects of pollution and other economic crops planting countries, the pollution of heavy metal elements in the vicinity of Dian Zhen Liu Jia need to get the attention of the relevant departments.