Читать книгу Gardening Indoors and Under Glass - F. F. Rockwell - Страница 16

Manure of some sort is essential to the growing of plants in pots or boxes, both because of the plant-food it adds to the soil, and because it improves its mechanical condition and sponginess or water-holding quality. Thoroughly rotted horse manure or horse and cow manure mixed is by far the best. Cow manure alone, or pig manure, is lumpy and cold, and hen, sheep, pigeon or other special manures are not safe in the hands of the beginner, as they are one-sided, being especially rich in nitrogen and likely either to burn the plants or to cause too soft and watery growth.

This brings us to the point where it is necessary to say a few words about the theory of manures, for they are not all alike and what would be wise to give a plant under some circumstances under others would be quite wrong, just as you would not think of feeding beefsteak to a baby just recovering from the colic, while it might be a very good thing for a hungry man who was going to saw up your wood-pile.

Plants of all sorts—in pots, in the garden or in a ten-acre lot—require three kinds of food elements: nitrogen, phosphoric acid and potash. These elements may be fed to the plants in various forms; for instance, the nitrogen in hen manure, or in cottonseed meal, or in salts from the nitrate fields of Chile, known as nitrate of soda; the phosphoric acid from bone, or from acid phosphate (a ground rock treated with acid); the potash from wood ashes or from German potash salts (muriate or sulphate of potash). Plants, to do their best, require that all three elements shall be present in sufficient amounts to supply their wants.

It is not necessary, however, to go very deeply into the science of plant foods in order to grow plants successfully. Fortunately, manure rotted as described above, furnishes all three elements in about the right proportions. Cow, sheep, hen and pigeon manure are best used as described later, under "Liquid Manuring."