Geochemical Evaluation Of Land Quality On Town Of Ming Tomb Of Beijing

Based on soil nutrient and soil environment survey,combined with the evaluation results of air quality,irrigation water quality,and agricultural product safety,the author carried out geochemical land quality evaluation in the town of Ming Tomb,located in Changping District of Beijing.Through above analyses,we made the following conclusions:1.The grading standard values of soil nutrients are in accordance with the classification given by the Chinese agricultural division data.I applied a single indicator evaluation method to category N,P,K,and soil organic carbon(SOC)into five classes.The classification results were indicated that the total nitrogen(N)content was at the lack slight lack level,P,K was at slight abundant and abundant level,and SOC was at the moderate level.The level of the comprehensive evaluation of soil nutrients was 3.2.The category classification results of geochemical soil environment showed that the soil environment in most of study area was clean,while Cd,Pb,Ni were polluted in part.Hence,the comprehensive environmental quality was clean or less clean.3.The quality of irrigation water and atmospheric wet and dry deposition were excellent.The soil nutrients content of organic fertilizer were abundant and harmful elements such as heavy metals were lower than the standard,which conform to the requirement for constructing the base of green food products.4.K,Ca,Cu,P,Fe content enriched in specialized agricultural products including persimmon,jujube,cherry and apple trees.There are positive correlations between the quality of agricultural products and geochemical elements in the soil.5.Based on geochemical land quality evaluation,there was most of the study area containing high content of Se.Moreover,there was 15% of the study area(23.52km~2)in which the content of Se was over 0.4mg/kg.They were mainly located around Lao juntang,Dong shui yu,Ding linggou,Zhui jiu yu,and so on.In addition,available Se content was very high in Se-rich areas.6.It was found that the contents of Hg and Au in the total 13 Ming tombs soil were very high and Hg content in part of study area exceeded the environmental quality standard,and have a certain impact on environmental quality.We will resolve the soil pollution problem and dynamic monitor the basic agriculture quality,at the same time,we will provide relative departments with the planning suggestions for developing agriculture products and exploiting the Se enriched soil according to the geochemical land quality evaluation results.