江西省土壤可溶态稀土元素含量和分布规律的研究

对江西 1 1种母质发育的有代表性的水稻土、旱作地、自然土壤 ,61个剖面 ,4 1 2个土样的可溶态稀土元素分析测定 ,统计结果表明 :江西土壤稀土元素的强度因素处于较高水平 ,平均值为 1 9 0mg/kg ,有 4 2 80 %的样点处于丰富级 ;有由南向北 ,由东向西逐渐降低的趋势 .其含量最高的地区是赣南由花岗岩、泥质岩、第四纪红粘土、酸性紫色土、碳质岩类风化物等母质发育的土壤 ,较低的为赣西北由石英岩 ,第三纪红砂岩、石灰岩、下蜀系黄土等母质发育的土壤 ;在土壤剖面分布中 ,旱作地表层低于底层 ,水稻土表层有生物富集作用高于底层 ;影响土壤中可溶态稀土元素含量的主要因子有 :成土母质 ,气候条件 (温度 ,降水量 ) ,土壤 pH ,土壤质地和耕作类型

Content and distribution pattern of soluble rare earth elements in Jiangxi province

The soluble rare earth elements content of 412 soil samples, including those taken from 61 soil profiles, were determined. The samples were taken from typical paddy fields, drylands and natural soils, which were developed from eleven types of parent materials in Jiangxi Province. The contents of rare earth elements in the soils averaged to 19 0mg/kg, being in a relatively high level, and 42 8% of them being graded as abundance. There existed a progressively decrease trend from south to north. The soils in the south were classified as red clay soil from granite, pelite and quaterary sediment as well as acidic purple soil from weathered carbonaceous rock, both soils containing higher level of rare earth elements. The soils in the north are yellow soils from quartzite, tertiary red sandstone, calcareous rock and subordinate, being lower in rare earth elements. As to the distribution pattern of rare earth elements in the soil profiles, the element contents in surface were lower than those in subsoil in drylands, while an opposite tendency was found for paddy fields due to biological contribution. The major factors, influencing the contents of soluble rare earth elements in soil, included parent materials, climatic elements, soil pH and texture.