我国土壤中可提取态钛含量与分布的初步研究

我国土壤中可提取态钛含量（0.02mol/L EDTA+0.5%NH#-4Cl为提取剂）为0-7.0ppm，平均为0.86ppm（以钛计算）。74%的标本低于1ppm,低于0.5ppm的占52%。我国土壤中可提取态钛含量总趋势为东北地区土壤含量高于南方土壤，华北地区及黄土高原、西北地区土壤含量最低。土壤中可提取态钛含量受到成土母质、土壤类型、土壤条件(pH、有机质含量)以及耕作熟化过程的影响。一般为玄武岩、页岩发育的土壤可提取态钛含量高于花岗岩、砂岩、浅海相沉积物发育的土壤；有机质含量高的土壤高于有机质含量低的土壤；耕作熟化的水稻土大于旱作土壤；森林土壤高于农田土壤。

CONTENT AND DISTRIBUTION OF EXTRACTABLE TITANIUM IN SOILS OF CHINA

Extractable Ti (EDTA NH_4CI) of China ranges from trace to 7.0 ppm (Ti) and the mean is 0.86 ppm. Content and distribution of extractable Ti in the Northeast China are the highest, then in the South China and lowest in the North China and Loess Plateau. And the variation of extractable Ti is primarily due to soil type and parent material, and secondly, soil pH and content of soil organic matter, and then process of uitilization and tillage. In general, contents of extractable Ti of soils from basalt and shale are higher than those from granite, sandstone, and shallow sea deposits; those of extractable Ti of soils with higher content of organic matter are higher than those with the lower content of organic matter; paddy soils higher than upland soils, and forest soils higher than agricultural soils.