Source Apportionment And Land Planning For Soil Selenium Of Typical Selenium Rich Area In Shandong

Selenium is a rare dispersed element which is also one of the essential micronutrients for the human body.As the study of selenium deepened,the positive effect of selenium on human health receives more and more attention.However,China is not a country with rich selenium resources,and there is a clear selenium deficiency zone in the NE-SW direction.Shandong Province where the study areas are located is in this zone.The soil selenium content is generally low in Shandong,but there are still some selenium rich regions in it.Therefore,it is very important to study the distribution and source of selenium elements in these typical areas with abnormal selenium content.Based on the research of environmental quality of soils in Shandong,this research selected four typical selenium rich research areas,Zhangqiu,Laiwu,Zaozhuang and Huantai.The distribution of selenium has been figured out by collecting the soil,crops,fertilizer,water and other samples.The source of the selenium has been work out by calculating the input and output flux and multivariate statistics.Finally,we will make long-term land planning for the selenium rich areas combined with several factors.This will provide theoretical basis and reasonable advice on how to utilize the resources of rich selenium continuously.The main conclusions of this study are as follows:The average contents of selenium in the four research areas are similar.They are in 0.28～0.33mg/kg and relatively high,which are basically above the Se-adequate level and has value of exploitation and utilization.The distribution of selenium elements in soil and soil profiles shows the distribution characteristic of surface accumulation.The parent material is the main factor controlling the vertical distribution of selenium elements.The study of selenium input and output flux in the study area shows that the main input approach of selenium in Zhangqiu,Zaozhuang and Huantai is atmospheric deposition,followed by irrigation.As for Laiwu,the main input approach is irrigation.It’s obvious that the flux of selenium in atmospheric deposition in Shandong is significantly higher than that in other provinces.There is a significant positive correlation between selenium content in deposition and surface soil,and its source may be closely related to combustion and emission of industrial fuel such as coal.The source of selenium in the irrigation water in Laiwu may be related to the industrial emissions.The study on the net selenium flux of soil in research areas shows that the content of soil selenium in the four research areas will increase continuously in the future.The soil quality in the study area is generally good except for Cd and Zn which are slightly polluted.Finally,131 thousand acres of selenium rich soil and 138 thousand acres of potential selenium rich soil planning area were delineated in four research areas.