Page:Popular Science Monthly Volume 35.djvu/103

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manufacture of an article of prime necessity, whose habitat has been for a century in the tropics.

The chemists have found that the four principal elements which enter into plant-life are met every day, only under other names and slightly different forms. Nitrogen in one form is the ammonia of commerce. Potash is simply lye from wood-ashes. Phosphoric acid is ground bones dissolved in acid; and lime is seen everywhere. These represent the necessary nutrition of the beet-root when the climatic conditions are favorable; but if they exist in insoluble combination, they will be useless in the economy of nutrition, or if in form suitable for similation, but excessive in quantities, they will stimulate the plant to abnormal growth, unsuited to its desired perfection.

The scientists have shown us how to cultivate the beet for sugar making; that soils charged with mineral salts are injurious to its development for that purpose; that, in fact, the beet easily absorbs saline matters, while the alkaline salts constitute one of the greatest obstacles to sugar extraction. They say new ground, or that lately cleared of forest, should not be applied to the culture of the beet, but the land used for this purpose should have been under continued cultivation at least ten or fifteen years for the removal of the nitrates and the organic matter containing nitrogen, which are always present in new soils, and exert an injurious influence on the quality of the root.

We now have elaborate tables of analyses of soils to show the chemical composition of those most favorable to the culture, as well as to the physical character which render them best suited to the cultivation of the beet, their porosity and subsoil conditions.

Unless the supply of the elements of plant-food is continuous and regular, a purely sandy soil would be undesirable. If no means are provided for the removal of surplus water which may be found in a purely clay soil, or to so improve its condition as to admit of free circulation of air as well as water, it will be too heavy, and become absolutely useless. The same is true of purely calcareous soil, since the same unfavorable conditions would prevail, though perhaps to not quite the same extent. Such soils would also be unsuited to the plant itself, because they would not admit of the free progress of the tap-root nor of the lateral fibrous roots in their search for nutrition. These conditions have a powerful influence upon the ultimate yield of sugar from the surface cultivated.

But if the sandy soil be mixed with either or both of the others, and with humus—pulverulent brown earth—in suitable proportions, the conditions most favorable to the maintenance of a regular and plentiful supply of food, the healthy condition of the root and its consequent normal development will be assured.