Selenium,Zinc Element Geochemical Characteristics And Land Resource Zoning In Ruijin Soil,Jiangxi

The paper selected the“Red Capital City”Ruijin City area,covering the surface layer of soil samples and crops and their corresponding root soils.Using geochemical survey data and geological information,the spatial distribution characteristics of zinc,selenium,nitrogen,phosphorus,potassium and pH values in soil were studied.The elemental statistical factors,correlation analysis,elemental prediction model and random forest model were used to investigate the factors affecting the activity of selenium and zinc in the topsoil.Divide the soil pollution level,and divide the green selenium-rich or zinc-rich farmland according to the land use type and the soil selenium-rich or zinc-rich degree.The average content of Se in the soil sample was 0.26 mg/kg,and 24.29%of the samples reached the selenium-enriched soil standard.Through the correlation analysis of Se and Zn,the influencing factors of the activity of Se and Zn were discussed.The Se content was negatively correlated with pH and positively correlated with the proportion of organic matter.Correlation analysis was carried out on the factors affecting the bioavailability of Se.It was found that the local economic crops of Ruijin,lotus seeds,bayberry and tea,had high selenium enrichment rate,and the Se content of crops and root soils was proportional.The richness of Se and Zn in crops.The set factor decreases as the pH of the soil increases.In the soil and crop discovery research area of the study area,the soil was not rich in selenium,and the selenium in the crops was studied.The Se enrichment of lotus seeds and roots was studied.It was concluded that the evaluation criteria of selenium-rich lotus soil in Ruijin area could be reduced to 0.3 mg/kg.And establish a bioavailability model model of crop seedling Se:Log?SeLotus?=0.036×Al₂O₃+0.109×Mo-0.031×LOIsoil-0.905×log?CaOsoil?-1.683Zn is highly correlated with Ni and positively correlated with V,Mn,Co and organic matter.Observing the spatial distribution characteristics of Zn content,Zn is controlled by pH and enriched in the neutral region of pH.Correlation analysis was carried out on the factors affecting the bioavailability of Zn.The enrichment coefficient of Zn in crop peanuts,Chinese bayberry and tea was proportional to the Zn content in root soil,while Zn in lotus seeds was not related to soil Zn content.The activity prediction model of soil Zn was established and the zinc-rich soil in Ruijin Jiubao area was predicted.The results were similar to the measured height:Zn=8.72+5.721×K+1.6×logNi+0.089×log Cd+0.498×log V-651.645×CrThe study found that the content of selenium and zinc in the topsoil has a strong correlation with the corresponding strata.The high value area of selenium in the soil is mainly concentrated in the Cretaceous,Quaternary and Carboniferous strata.Organic matter is formed in the black rock system of the parent material.Soil zinc is also highly enriched in the Permian.