摘要
利用XRD、粒度分析、土壤风化模拟试验等方法,对黄土区土壤有效硅含量分布、土壤机械组成、粘粒矿物种类及含量分布、土壤溶液pH值和土壤矿物风化过程中硅的析出规律进行研究。从陕北干旱区到关中半湿润区,土壤中蛭石含量从0.18%升高到1.60%;高岭石从0.45%升高到1.84%,相应的土壤有效硅含量从122.62×10-6升高到463.95×10-6。土壤有效硅含量与粘粒矿物总量呈正比,与土壤溶液pH值成反比,这与南方水田水稻土情况完全不同。模拟实验证实土壤中存在的游离硅是硅酸盐矿物异成分溶解的结果。研究区土壤风化作用强度规律性变化是造成区内土壤有效硅含量变化的主要原因。
The content and distribution of available silicon, grain size, clay minerals in the soil, pH of soil solution, and silicon solubility in the weathering process were studied by means of XRD, grain-size analysis and simulating experiment on soil weathering. The contents of vermiculite are from 0.18% up to 1.60% and those of kaolinite from 0.45% up to 1. 84% from arid area （Shanbei） to semi-humid area （Guanzhong Basin）. The contents of available silicon in the soil are positively correlated with the contents of clay minerals and negatively with the pH of soil solution. This is not the case for paddy soil in southern China. A simulating experiment on soil weathering showed that the free silicon comes from dissolution of silicate. The variation of available silicon was controlled by the variation of weathering intensity in the area studied.
出处
《矿物学报》
CAS
CSCD
北大核心
2006年第2期189-195,共7页
Acta Mineralogica Sinica
基金
陕西省教育厅重点产业化项目阶段性成果(项目编号:2002JC10)
关键词
有效硅
粘粒矿物
黄土
风化作用
available silicon
clay mineral
soil in loess area
weathering
