Spatial distribution characteristics of natural organochlorine in topsoil of Hetao Plain
To find out the distribution and influencing factors of natural organochlorine(Clorg)in the topsoil of Hetao Plain,this work collected 55 topsoil samples(0-20 cm)from Hetao Plain to analyze the soil physical and chemical properties(texture,pH,total organic carbon)and the content of different forms of chlorine.Descriptive statistics and correlation analysis show that natural Clorg content ranges from 18.84 to 182.75 mg/kg(mean value of 56.06 mg/kg),accounting for 1.74%-92.81%of the total chlorine(Cltot).The natural Clorg content in the western alluvial fan plain of the Yellow River is higher than that in the eastern floodplain.The content of natural Clorg in the topsoil is related to the chloride(Cl-)content and soil pH value,except total organic carbon(TOC)content.Soil texture obviously affects the content of natural Clorg in topsoil,and the average value is the highest in sandy loam.It is concluded that natural Clorg is ubiquitous in the study area topsoil,and the spatial distribution of natural Clorg is affected by Cl-,TOC,pH and soil texture jointly.High Cl-content,low pH value and sandy loam are favorable conditions for the natural Clorg accumulation in the topsoil,while this influence is insignificant from TOC content at high salinity levels.
natural organochlorinespatial distribution characteristictopsoilHetao Plain