The Elements of Agriculture A Book for Young Farmers, with Questions Prepared for the Use of Schools - George E. Waring (bill gates books to read txt) 📗

manure every thing that is necessary for the formation of the ash of that plant. This would give a good crop on any soil that was in the proper mechanical condition, and contained enough organic matter; but a moment's reflection will show that, if the soil contained a large amount of potash, or of phosphate of lime, it would not be necessary to make an application of more of these ingredients--at an expense of perhaps three times the cost of an analysis. It is true that, if the crop is sold, and it is desired to maintain the fertility of the soil, the full amount of the ash must be applied, either before or after the crop is grown; but, in the ordinary use of crops for feeding purposes, a large part of the ash will exist in the excrements of the animals; so that the judicious farmer will be able to manure his land with more economy than if he had to apply to each crop the whole amount and variety required for its ash. SECTION 3 (MANURES) CHAPTER VIII (MINERAL MANURES) Pg 139

 

The best rule for practical manuring is probably to strengthen the soil in its weaker points, and prevent the stronger ones from becoming weaker. In this way, the soil may be raised to the highest state of fertility, and be fully maintained in its productive powers.

2d. Those manures which render available matter already contained in the soil.

[How may silica be developed?

How does lime affect soils containing coarse particles?

How do mineral manures sometimes improve the mechanical texture of the soil?]

Silica (or sand), it will be recollected, exists in all soils; but, in its pure state, is not capable of being dissolved, and therefore cannot be used by plants. The alkalies (as has been stated), have the power of combining with this silica, making compounds, which are called silicates. These are readily dissolved by water, and are available in vegetable growth. Now, if a soil is deficient in these soluble silicates, it is well known that grain, etc., grown on it, not being able to obtain the material which gives them strength, will fall down or lodge; but, if such measures be taken, as will render the sand soluble, the straw will be strong and healthy. Alkalies used for this purpose, come under the head of those manures which develope the natural resources of the soil.

Again, much of the mineral matter in the soil is combined within particles, and is therefore out of the reach of roots. Lime, among other thing, has the effect of causing these particles to crumble and expose their constituents to the demand of roots.

SECTION 3 (MANURES) CHAPTER VIII (MINERAL MANURES) Pg 140

 

Therefore, lime has for one of its offices the development of the fertilizing ingredients of the soil.

3d. Those manures which improve the mechanical condition of the soil.

The alkalies, in combining with sand, commence their action on the surfaces of the particles, and roughen them--rust them as it were. This roughening of particles of the soil prevents them from moving among each other as easily as they do when they are smooth, and thus keeps the soil from being compacted by heavy rains, as it is liable to be in its natural condition. In this way, the mechanical texture of the soil is improved.

It has just been said that lime causes the pulverization of the particles of the soil; and thus, by making it finer, improves its mechanical condition.

Some mineral manures, as plaster and salt, have the power of absorbing moisture from the atmosphere; and this is a mechanical improvement to dry soils.

[Name some mineral manures which absorb ammonia?]

4th. Those mineral manures which have the power of absorbing ammonia.

Plaster, chloride of lime, alumina (clay), etc., are large absorbents of ammonia, whether arising from the fermentation of animal manures or washed down from the atmosphere by rains. The ammonia thus absorbed is of course very important in the vegetation of crops.

Having now explained the reasons why mineral manures are necessary, and the manner in which they produce their effects, we will proceed to examine the various deficiencies of soils and the character of many kinds of this class of fertilizers.

SECTION 3 (MANURES) CHAPTER IX (DEFICIENCIES OF SOILS, MEANS OF RESTORATION, ETC) Pg 141

As will be seen by referring to the analyses of soils on p. 72, they may be deficient in certain ingredients, which it is the object of mineral manures to supply. These we will take up in order, and endeavor to show in a simple manner the best means of managing them in practical farming.

ALKALIES.

POTASH.

[Do all soils contain a sufficient amount of potash?

How may its deficiency have been caused?

How may its absence be detected?

Does barn-yard manure contain sufficient potash to supply its deficiency in worn-out soils?]

Potash is often deficient in the soil. Its deficiency may have been caused in two ways. Either it may not have existed largely in the rock from which the soil was formed, and consequently is equally absent from the soil itself, or it may have once been present in sufficient quantities, and been carried away in crops, without being returned to the soil in the form of manure until too little remains for the requirements of fertility.

SECTION 3 (MANURES) CHAPTER IX (DEFICIENCIES OF SOILS, MEANS OF RESTORATION, ETC) Pg 142

 

In either case, its absence may be accurately detected by a skilful chemist, and it may be supplied by the farmer in various ways. Potash, as well as all of the other mineral manures, is contained in the excrements of animals, but not (as is also the case with the others) in sufficient quantities to restore the proper balance to soils where it is largely deficient, nor even to make up for what is yearly removed with each crop, except that crop (or its equivalent) has been fed to such animals as return all of the fertilizing constituents of their food in the form of manure, and this be all carefully preserved and applied to the soil. In all other cases, it is necessary to apply more potash than is contained in the excrements of animals.

[What is generally the most available source from which to obtain this alkali?

Will leached ashes answer the same purpose?

How may ashes be used?]

Unleached wood ashes is generally the most available source from which to obtain this alkali. The ashes of all kinds of wood contain potash (more or less according to the kind--see analysis section V.) If the ashes are leached, the potash is removed; and, hence for the purpose of supplying it, they are worthless; but unleached ashes are an excellent source from which to obtain it.

SECTION 3 (MANURES) CHAPTER IX (DEFICIENCIES OF SOILS, MEANS OF RESTORATION, ETC) Pg 143

 

They may be made into compost with muck, as directed in a previous chapter, or applied directly to the soil. In either case the potash is available directly to the plant, or is capable of uniting with the silica in the soil to form silicate of potash. Neither potash nor any other alkali should ever be applied to animal manures unless in compost with an absorbent, as they cause the ammonia to be thrown off and lost.

[From what other sources may potash be obtained?

How may we obtain soda?

In what quantities should pure salt be applied to the soil?]

Potash sparlings, or the refuse of potash warehouses, is an excellent manure for lands deficient in this constituent.

Potash marl, such as is found in New Jersey, contains a large proportion of potash, and is an excellent application to soils requiring it.

Feldspar, kaolin, and other minerals containing potash, are, in some localities, to be obtained in sufficient quantities to be used for manurial purposes.

Granite contains potash, and if it can be crushed (as is the case with some of the softer kinds,) it serves a very good purpose.