VEGETABLE NUTRITION.

Colonist, Volume IV, Issue 371, 14 May 1861, Page 4

VEGETABLE NUTRITION.

The theory of vegetable nutrition, as enunciated by Baron Liebig, may be stated in the following terms: —

As all plants are known to contain certain organic and inorganic or mineral ingredients, derived either from the atmosphere by the leaves, or from the soil by the roots, it follows that whatever is taken directly from the soil must, according to the quantity more or less reduce its fertility. The mineral food of plants derived from the soil and found in their ashes cannot be dispensed with; therefore all soils poor in such mineral matter are infertile, and can be rendered productive only by the application of farm-yard or other manures containing the necessary mineral substances. To render mineral matters present in the soil serviceable in the nourishment of plant-life, they mu6t be found in a soluble state, and any agent capable of increasing its solubility will, of necessity, become a fertillizer. Both carbonic acid and sulphuric acid, when brought in a state of solution into contact with certain insoluble mineral ingredients in the soil, decompose and render them soluble; and hence sulphates and carbonates used as manure are partially decomposing agents, and assist atmospheric action in the soil.. But plants require food directly from the atmosphere, as well as from the soil, and certainly derive a large proportion of both their carbon and their ammonia from the air. The proportions in which these substances are assimilated from the atmosphere, either by their leaves or from the soil after being acted upon by it, depend upon the co-opsration of the mineral constituents present in the soil. When the soil is in the best possible condition in respect to culture, and the supply of the various mineral substance required by plants, the atmosphere will afford sufficient carbon and ammonia to bring them to maturity; but as the time of growth is limited, a supply of ammonia and carbon to the soil in the form ol carbonaceous and nitrogenous manures will be necessary to secure a maximum crop.