The Elements of Agriculture A Book for Young Farmers, with Questions Prepared for the Use of Schools, George E. Waring [read aloud books TXT] 📗

the soil; and therefore, when used alone, should always be applied as a top dressing to be carried into the soil by rains. The tendency of lime to settle is so great that, when cutting drains, it may often be observed in a whitish streak on the top of the subsoil. After heavy doses of lime have been given to the soil, and have settled so as to have apparently ceased from their action, they may be brought up and mixed with the soil by deeper plowing.

Lime should never be mixed with animal manures, unless in compost with muck, or some other good absorbent, as it is liable to cause the escape of their ammonia.

SECTION 3 (MANURES) CHAPTER IX (DEFICIENCIES OF SOILS, MEANS OF RESTORATION, ETC) Pg 155

 

PLASTER OF PARIS.

Plaster of Paris or Gypsum (sulphate of lime) is composed of sulphuric acid and lime in combination. It is called 'plaster of Paris,' because it constitutes the rock underlying the city of Paris.

[Is it a constituent of plants?

What else does it furnish them?

How does it affect manure?

How does it produce sorrel in the soil?

How may the acidity be overcome?]

It is a constituent of many plants. It also furnishes them with sulphur--a constituent of the sulphuric acid which it contains.

It is an excellent absorbent of ammonia, and is very useful to sprinkle around stables, poultry houses, pig-styes, and privies, where it absorbs the escaping gases, saving them for the use of plants, and purifying the air, thus rendering stables, etc., more healthy than when not so supplied.

It has been observed that the extravagant use of plaster sometimes induces the growth of sorrel. This is probably the case only where the soil is deficient in lime. In such instances, the lime required by plants is obtained by the decomposition of the plaster. The lime enters into the construction of the plant, and the sulphuric acid remains free, rendering the soil sour, and therefore in condition to produce sorrel. In such a case, an application of lime will correct the acid by uniting with it and converting it into plaster.

SECTION 3 (MANURES) CHAPTER IX (DEFICIENCIES OF SOILS, MEANS OF RESTORATION, ETC) Pg 156

 

CHLORIDE OF LIME.

[What does chloride of lime supply to plants?

How does it affect manures?

How may it be used?

How may magnesia be supplied, when wanting?

What care is necessary concerning the use of magnesia?]

Chloride of lime is a compound of lime and chlorine. It furnishes both of these constituents to plants, and it is an excellent absorbent of ammonia and other gases arising from decomposition--hence its usefulness in destroying bad odors, and in preserving fertilizing matters for the use of crops.

It may be used like plaster, or in the decomposition of organic matters, where it not only hastens decay, but absorbs and retains the escaping gases. It will be recollected that chloride of lime is one of the products of the lime and salt mixture.

Lime in combination with phosphoric acid forms the valuable phosphate of lime, of which so large a portion of the ash of grain, and the bones of animals, is formed. This will be spoken of more at length under the head of 'phosphoric acid.'

SECTION 3 (MANURES) CHAPTER IX (DEFICIENCIES OF SOILS, MEANS OF RESTORATION, ETC) Pg 157

 

MAGNESIA.

Magnesia is a constituent of vegetable ashes, and is almost always present in the soil in sufficient quantities. When analysis indicates that it is needed, it may be applied in the form of magnesian lime, or refuse epsom salts, which are composed of sulphuric acid and magnesia (sulphate of magnesia).

The great care necessary concerning the use of magnesia is, not to apply too much of it, it being, when in excess, as has been previously remarked, injurious to the fertility of the soil. Some soils are hopelessly barren from the fact that they contain too much magnesia.

ACIDS.

SULPHURIC ACID.

[What is sulphuric acid commonly called?

How may it be used?

How does it prevent the escape of ammonia?]

Sulphuric acid is a very important constituent of vegetable ashes, especially of oats and the root-crops.

It is often deficient in the soil, particularly where potatoes have been long cultivated. One of the reasons why plaster (sulphate of lime) is so beneficial to the potato crop is undoubtedly that it supplies it with sulphuric acid.

Sulphuric acid is commonly known by the name of oil vitriol, and may be purchased for agricultural purposes at a low price. 

SECTION 3 (MANURES) CHAPTER IX (DEFICIENCIES OF SOILS, MEANS OF RESTORATION, ETC) Pg 158

 

It may be used in a very dilute form (weakened by mixing it with a large quantity of water) to the compost heap, where it will change the ammonia to a sulphate as soon as formed, and thus prevent its loss, as the sulphate of ammonia is not volatile; and, being soluble in water, is useful to plants. Some idea of the value of this compound may be formed from the fact that manufacturers of manures are willing to pay seven cents per lb., or even more, for sulphate of ammonia, to insure the success of their fertilizers. Notwithstanding this, many farmers persist in throwing away hundreds of pounds of ammonia every year, as a tax for their ignorance (or indolence), while a small tax in money--not more valuable, nor more necessary to their success--for the support of common schools, and the better education of the young, is too often unwillingly paid.

[What is the effect of using too much sulphuric acid?]

If a tumbler full of sulphuric acid (costing a few cents), be thrown into the tank of the compost heap once a month, the benefit to the manure would be very great.

Where a deficiency of sulphuric acid in the soil is indicated by analysis, it may be supplied in this way, or by the use of plaster or refuse epsom salts.

Care is necessary that too much sulphuric acid be not used, as it would prevent the proper decomposition of manures, and would induce a growth of sorrel in the soil by making it sour.

In many instances, it will be found profitable to use sulphuric acid in the manufacture of super-phosphate of lime (as directed under the head of 'phosphoric acid,') thus making it perform the double purpose of preparing an available form of phosphate, and of supplying sulphur and sulphuric acid to the plant.

SECTION 3 (MANURES) CHAPTER IX (DEFICIENCIES OF SOILS, MEANS OF RESTORATION, ETC) Pg 159

 

PHOSPHORIC ACID.

[How large a part of the ashes of grain consists of phosphoric acid?

Of what other substances does it form a leading ingredient?

How many pounds of sulphuric acid are contained in one hundred bushels of wheat?]

We come now to the consideration of one of the most important of all subjects connected with agriculture, that is, phosphoric acid.

Phosphoric acid, forming about one half of the ashes of wheat, rye, corn, buckwheat, and oats; nearly the same proportion of those of barley, peas, beans and linseed; an important ingredient of the ashes of potatoes and turnips; one quarter of the ash of milk and a large proportion of the bones of animals, often exists in the soil in the proportion of only about one or two pounds in a thousand. The cultivation of our whole country has been such, as to take away the phosphoric acid from the soil without returning it, except in very minute quantities. Every hundred bushels of wheat sold contains (and removes permanently from the soil) about sixty pounds of phosphoric acid. Other grains, as well as the root crops and grasses, remove likewise a large quantity of it.

SECTION 3 (MANURES) CHAPTER IX (DEFICIENCIES OF SOILS, MEANS OF RESTORATION, ETC) Pg 160