烟草根际土壤硒、硫形态相互作用与烟草对硒、硫吸收的研究

Interaction of Se and S forms in rhizospheric soil and their absorption by tobacco

通过烟草根际营养试验研究发现 ,烟草根际土壤Se总量及可溶态Se、交换态Se及有机Se均表现出明显的亏缺 .而根际土中S总量及吸附性S、有机S则表现明显的富集 .施S对根际土Se亏缺程度的影响与施Se处理有关 ,而施Se对根际土S富集程度的影响随施S的水平而有一定差异 .未施Se处理时 ,施S降低了烟草根际土中相应几种Se形态的亏缺率 ,施Se处理时施S的影响则相反 .不施S时 ,加入Se可以增加根际土全S量的富集程度 ;施S时 ,加入Se则减少根际全S量的富集程度 .前期烟草的Se含量主要受根际土壤可溶态Se的影响 ,而Se积累量除受土壤可溶态Se的影响外 ,还受到根际土壤交换态Se、有机Se及酸溶态Se的影响 .

Pot experiment with tobacco shows that the amount of total,solube,exchangeable and organic Se in rhizospheric soil appeared depletory,while that of total,adsorbed and organic S appeared enriched.The influence of added S on Se depletion depended on the level of Se application,and that of added Se on S enrichment depended on the rate of S applicagtion.In the absence of added Se,the addition of S decreased the depletion of several Se forms ;while in its presence,the reverse result was obtained.The addition of Se increased the enrichment of total S when the S was not added.With S application,the added Se reduced the enrichment of total S.At early stage,teh Se content of tobacco was mainly influenced by the soluble Se in rhizospheric soil,while the accumulated amount of Se in tobacco was also influenced by exchangeable,organic and acid soluble Se.The S content in the aboveground part of tobacco at its early stage was mainly influenced by soluble and organic S in the rhizosphere.