Chapter VIII

Of the Improvement of the Soil—Mechanical and Chemical
Methods—Draining—Subsoiling—Ploughing, and Mixing
of Soils—Use of Lime, Marl, and Shell-sand—Manures
—Vegetable, Animal, and Mineral Manures.

The soil is possessed of certain existing and obvious qualities, and of certain other dormant capabilities; how are these qualities to be improved,—these dormant capabilities to be awakened?

There are two distinct methods by which these ends may be, in some measure, attained,—by the use of _mechanical_, and by the application of _chemical_, means. Mechanical operations produce changes _chiefly_ in the physical properties of the soil,—chemical means alter its elementary constitution. Ploughing, draining, mixing, &c. belong to the former class of operations; manuring and irrigation belong to the latter. It will be proper to consider these methods separately.