西藏日喀则地区栽培牧草中7种微量元素的分布特征

Distribution characteristic of trace elements in pastures from Tibet

通过对西藏日喀则地区3科43种栽培牧草中的铁、锰、钼、铜、锌、硒、钴7种微量元素的测定,探究微量元素在不同科属牧草中的分布特征。结果表明,西藏日喀则地区栽培牧草中微量元素的分布存在一定的规律性。总体而言,铁含量最高,可达800μg/g;锌次之,最高接近200μg/g;硒含量最低,含量变幅为0.002-0.013μg/g。3科牧草中,禾本科牧草铁含量相对较低,锌、铜含量相对较高;藜科牧草锌、铜含量相对较低,铁、锰含量相对较高;豆科牧草多数微量元素含量相对居中;各科牧草中的铁、锌、铜含量均属较高水平,钴均属中等水平;锰、硒、钼在3科间含量水平不一致。

7 kinds trace elements of 43 species in 3 families of pastures from Tibet,including iron（Fe）,manganese（Mn）,molybdenum（Mo）,copper（Cu）,zinc（Zn）,selenium（Se） and cobalt（Co）,were determined to study the distribution characteristic of trace elements in pastures among different families and genus.The results showed that the distribution of trace elements in pastures from Tibet presented certain regularity.Overall,the content of Fe was the highest,the content of Zn was the second,and the content of Se was the lowest.Among 3 families,Gramineae pastures had low Fe content,but high Zn and Cu content,whereas Chenopodiaceae pastures had low content of Zn and Cu,but high content of Fe and Mn.The contents of most of trace elements in Leguminosae pastures were at mediate levels.In cultivated pastures from Tibet,the contents of Fe,Zn and Cu were all high levels;Co content was middle level;but the levels of Mn,Se and Mo contents were not the same among different families.