Agriculture Reference
In-Depth Information
Table I.2 presents the indicative total concentrations of selected major and minor
elements in surface soils together with the ranges that may be expected to occur in areas
where mineralisation has occurred or which have been polluted by human activities.
Comparison of the concentrations of the major elements in Tables I.1 and I.2 shows
that, on average, the less mobile elements (Al, Fe) occur in soils at similar or greater
concentrations than their averages in the earth's crust. They may become even more
concentrated in highly-weathered soils, due to the relatively greater losses of the more
soluble elements over time. Further, certain elements required by the biota, such as
Ca and P are also present in greater concentrations and C and N are important
components of soil organic matter that generally occur in insignificant concentrations
in the earth's crust.
