白浆土中铁和锰的含量与分布

IRON AND MANGANESE CONTENT AND DISTRIBUTION IN ALBIC PLANOSOL

白浆土母质是由河湖淤积而成,土壤质地粘重,土壤中铁锰的含量较高。而铁锰含量随着剖面粘重程度的增加亦增加。其中全铁和游离铁的含量,表层最低,白浆层居中,淀积层最高。全铁和游离铁的含量之间呈正相关。Yi_(游离铁)=0.075+0.365x,r=0.853^(**),n=12。络合态铁随着剖面的加深而含量逐渐降低。络合态铁的含量与土壤有机质的含量呈正相关。Y_(络铁)=158.8+109.2x,n=6,r=0.945^(**)。无定形铁在剖面中的变化,为表层和淀积层高而自浆层低。白浆土中铁向粘粒部分的富集率>1。全锰和活性锰的含量,表层最高,其次是白浆层,淀积层最低,随着剖面深度的加深而含量减少。白浆土铁锰在表层的含量较高,活性铁锰的含量也高,在一般生产条件下,能满足作物的需要,不必再施铁锰肥料。

The parent materials of planosols are formed on river and lake deposit with heavy texture and high Fe and Mn contents.The total Fe and isolated Fe contents are lowest in the surface soil and highest in the illuviated layer.Fe and Mn contents increase with clay content in the Profile.There is positive relation between total Fe and isolated Fe,Yiso·Fe=0.075+0.365X,r=0.853**, n=12.The complex Fe content decreases with the depth along the profile,and positively related to organic matter content.Ycomp·Fe=158.8+109.2X,n=6, r=0.945**.Amorphous Fe change in the profile is,high in surface soil and illu- vialed layer,but low in Aw layer.Rate of accumulation of Fe to clay portion is >1 in planosol. The total Mn and active Mn contents ares highest in surface layer,then the Aw layer,and lowest in illuviated layer,that is to say,decrease with depth of soil layer. Fe and Mn are high in surface layer of planosol,including active Fe and Mn thus in the ordinary production conditions they can meet the plant needs and not necessary to apply them as fertilizers.