Study on the Geochemical Characteristics of Germanium in Yueyang County

TANG Hengjia; LIAO Qi; LYU Xuxiang; LU Xin; LI Cong; CHEN Fangwei; MAO Xiong; YANG Pengzhi; WANG Pei

doi:10.19672/j.cnki.1003-6504.2106.24.338

Abstract：In recent years,the geochemical characteristics of soil elements in cultivated land area are more and more favored by researchers.Through the investigation and analysis of the characteristics and distribution of metal elements in the soil in cultivated land area,it can provide help for the adjustment of agricultural structure and the development of characteris-tic agricultural products.Germanium,as a dilute element,has great application prospects in biomedical,electronic industry and optical industry,and is closely related to the growth of plants in soil.Based on the basis of 1∶50 000 topographic map,2 784 surface soil samples from the cultivated area of Yueyang County were collected,and the vertical profile results of differ-ent strata(22 points,a total of 148 samples)were added to compare the surface column samples,so as to help explain the causes of germanium enrichment.In the soil samples,heavy metal elements,nutrient elements(potassium,sodium,calcium and magnesium),organic carbon and other indicators were tested respectively,and the influence of soil pH value,organic matter content,land use type,soil type,soil parent matter and heavy metal content on the distribution characteristics of germa-nium in the cultivated land area was studied.The results showed that the average content of germanium in the surface soil of the study area was 1.547 mg/kg,Higher than the national background value,slightly lower than the soil background value of Hunan Province.Distribution is affected by soil matrix(mainly granite,plate shale,conglomerate),presents the characteristics of high northeast and low southwest.Germanium content in topsoil was negatively correlated with soil pH,organic carbon,Ca and Na,into a positive correlation with Mg and K,and widely distributed in the acid(pH＜6)and organic matter＜60 g/kg region.The main soil types in this region are mainly latent fertile rice soil,acidic purple soil and red soil.The main type of land use is the forest land,other grassland and orchards.Soil germanium content showed a significant positive correlation with arsenic,chromium,copper and zinc.A significant negative correlation with cadmium.It shows that the germanium element in the soil is closely related to the main heavy metal elements.Germanium content in the topsoil is up to 1.698 mg/kg in the Holocene alluvial formation unit.The germanium-rich formation units are mainly concentrated in the Baihuiting Formation and the Dongting Lake Formation.At the same time,the content of germanium in column soil is closely related to land use type and pH,while the correlation with organic matter and heavy metals is weakened,which indicates that the migration and enrichment of germanium in cylindrical soil is greatly influenced by land use type.