What must a farmer know in order to avoid failures? Can this be learned entirely from observation? What kind of action have manures? Give examples of each of these. May mechanical effects be produced by chemical action? How does potash affect the soil? To understand the science of manures is the most important branch of practical farming. No baker would be called a good practical baker who kept his flour exposed to the sun and rain. No shoemaker would be called a good practical shoemaker, who used morocco for the soles of his shoes, and heavy leather for the uppers. No carpenter would be called a good practical carpenter, who tried to build a house without nails, or other fastenings. So with the farmer. He cannot be called a good practical farmer if he keeps the materials, from which he is to make plants, in such a condition, that they will have their value We shall adopt a classification of the subject somewhat different from that found in most works on manures, but the facts are the same. The action of manures is either mechanical or chemical, or a combination of both. For instance: some kinds of manure improve the mechanical character of the soil, such as those which loosen stiff clay soils, or others which render light sandy soils compact—these are called mechanical manures. Some again furnish food for plants—these are called chemical manures. Many mechanical manures produce their effects by means of chemical action. Thus potash combines chemically with sand in the soil. In so doing, it It is important that this distinction should be well understood by the learner, as the words "mechanical" and "chemical" in connection with manures will be made use of throughout the following pages. What are absorbents? What kind of manure is charcoal? There is another class of manures which we shall call absorbents. These comprise those substances which have the power of taking up fertilizing matters, and retaining them for the use of plants. For instance, charcoal is an absorbent. As was stated in the section on soils, this substance is a retainer of all fertilizing gases and many minerals. Other matters made use of in agriculture have the same effect. These absorbents will be spoken of more fully in their proper places. TABLE.
Into what classes may manures be divided? What are organic manures? Inorganic? Atmospheric? Manures may be divided into three classes, viz.: organic, inorganic, and atmospheric. Organic manures comprise all animal and vegetable matters which are used to fertilize the soil, such as dung, muck, etc. Inorganic manures are those which are of a purely mineral character, such as lime, ashes, etc. Atmospheric manures consist of those organic manures which are in the form of gases in the atmosphere, and which are absorbed by rains and carried to the soil. These are of immense importance. The ammonia and carbonic acid in the air are atmospheric manures. FOOTNOTES: |