The combination of natural processes by which soils are formed.
1 Finally, the _plants _growing in soils are powerful agents of soil formation .
2 The most effective water impurity, considering soil formation , is the gas, _carbon dioxid.
3 The second great chemical agency of soil formation is the oxygen of the air.
4 We have learnt these things about soil formation .
5 While, therefore, the physical agencies of soil formation are most active in arid climates, the same cannot be said of the chemical agencies.
6 It is clear, then, that the second great agency of soil formation , which always acts in conjunction with temperature changes, is _freezing water.
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