| 1 |
 |
“...occurring tropical
soils, viz. the red earths and grey earths proved to exist differ-
ences not only mineralogically but physically and chemically
as well.
This especially stands out most clearly if you compare the
soils of a region with the same climate and flora but a different
parent rook. But also otherwise the contrasts continue to exist.
Mineralogically the red earths have much more opaque
components and a chiefly kaolinitic clay mineral. The grey
earths have however more dark minerals (pyroboles and
epidotes) and a principally montmorillonitic clay mineral.
Physically the grey earths are very heavy, with a slow water
movability and hard to till; the red earths on the contrary are
in general light soils with a quick water movability. Chemically
the grey earths are richer and more alkaline than the red earths.
They contain more carbonates, humus, nitrogen, salts, phos-
phoric acid and bases.
The red earths are often obviously poorer in them and have
a weak acid reaction.
CENTRAL! ItLIOTHEEK...”
|
|
