发育良好，土表下有一层粘土淀积土层。

These soils are well developed and contain a subsurface horizon in which clays have accumulated.

youdao

有效铁在红土母质中分布规律与全铁相反，在草甸黑土中表现出明显的淀积特征，其余各土类中有效铁含量分布与全铁一致。

Available Fe, on the other hand, had obvious illuviation in meadow black soil. Some other available Fe had the same rule with total Fe.

youdao

铁的活化度白浆土高于黑土，而白浆土的白浆层又高于腐殖质层和淀积层；

The activated degree of iron in Albisol is higher than That in Black Soil.

youdao