土壤砷污染对大豆砷含量与分布的影响

Effects of soil arsenic pollution on arsenic content and distribution in soybean

通过土壤加砷盆栽大豆实验,利用氢化物发生-分光光度法测定大豆和土壤的砷含量,以研究土壤砷污染对大豆砷含量及其分布的影响.结果表明,大豆根、茎和籽粒砷含量均与土壤加砷水平呈极显著的线性相关,并呈根〉茎〉籽粒的规律.大豆收获后,土壤砷含量与土壤加砷水平呈极显著的线性相关,土壤砷的残留率在82%以上,与土壤加砷水平呈极显著的对数相关.大豆根、茎和籽粒的富砷量均与土壤加砷呈极显著的二次函数相关关系,大豆茎的富砷量是根富砷量的3.4~8.1倍,是籽粒富砷量的2.8~4.6倍.大豆吸收的砷有82%以上存在于地上部分,但大豆对土壤加砷的利用率只在万分之几.大豆富砷量和大豆对土壤砷的利用率均以茎最高,而富集系数则为根〉茎〉籽粒.总之,大豆砷含量受土壤砷水平决定,籽粒含砷量最低有利于砷污染土壤的利用,土壤砷污染具有长效性.

A soil pot experiment was conducted to investigate the effects of soil arsenic pollution on arsenic content and distribution in soybean and arsenic contents in soybean and soil were determined by the method of hydride generation spectrophotometry.The results showed that arsenic content in soybean roots,stalks and grains were significant linearly correlative to soil arsenic additions and took on an order of rootsstalksgrains.The arsenic contents in soybean-harvested soils were significant linearly correlative to soil arsenic additions,but the residual rates of arsenic in soil were more than 82% and significant exponentially correlative to soil arsenic additions.There was a significant quadratic function relationship between the arsenic accumulations in soybean roots,stalks and grains and soil arsenic additions,but the soybean arsenic accumulations in stalks were 3.4-8.1 times as high as those in roots and 2.8-4.6 times as high as those in grains.Arsenic accumulations in soybean aerial parts were above 82% of total arsenic accumulations in soybean,while the utilization efficiency of soil arsenic additions in soybean were less than one-thousandth.Both the arsenic accumulation and utilization efficiency were the highest in stalks,but the enrichment factors decreased in an order of rootsstalksgrains.In summary,arsenic contents on soybean depended on soil arsenic levels and the lowest arsenic content in soybean grains was beneficial to utilize the arsenic pollution soils,but the aftereffects of arsenic pollution in soil lasted long.