Different plants have ashes of different composition. Thus—one may take from the soil large quantities of potash, another of phosphoric acid, and another of lime.
By understanding these differences, we shall be able so to regulate our rotations, that the soil may not be called on to supply more of one ingredient than of another, and thus it may be kept in balance.
How are farmers to be benefited by such knowledge?
The facts contained in this chapter are the alphabet of agriculture, and the learner should not only become perfectly familiar with them, but should also clearly understand the reasons why they are true, before proceeding further.
SECTION SECOND.
THE SOIL.
CHAPTER I.
FORMATION AND CHARACTER OF THE SOIL.
What is a necessary condition of growth?