NOTE I. (p. 225).

Difference in Amount of Excreta voided for Food consumed.

With regard to the difference in the composition of the solid excreta voided by different fattening animals fed on the same amount of food, see Warington's 'Chemistry of the Farm,' p. 125, where it is shown that for equal amount of live-weight, the sheep produces on the same weight of dry food very much more manure than the pig, while the ox produces even more than the sheep. Of course this does not refer to the total amount of manure produced by the different animals, but only to the amount of manure produced from the consumption of equal quantities of food. This would seem to be owing to the greater capacity the pig has for assimilating its food.

NOTE II. (p. 227).

Solid Excreta voided by Sheep, Oxen, and Cows.

To contrast with the analyses given by Stoeckhardt, it may be well to cite those based on Lawes and Gilbert's experiments, and quoted by Warington ('Chemistry of the Farm,' p. 138):—I.—Sheep (fed on meadow-hay).

II.—Oxen (fed on clover-hay and oat-straw, with 8 lb. beans per day).

III.—Cows (fed on mangels and lucerne hay).

NOTE III. (p. 232).

Urine voided by Sheep, Oxen, and Cows.

The following are the results for urine, the animals being fed as in Note II.:—

NOTE IV. (p. 233).

Percentage of Food voided in the Solid and Liquid Excrements.

According to Wolff, the following table shows the percentage of the dry substance of the food which is voided in the solid and liquid excrements of the cow, ox, sheep, and horse:—

NOTE V. (p. 234).

Pig Excrements.

The excrements voided by pigs are poor in manurial constituents, because the food on which they are fed is generally of a very poor nature. In their case the urine is always very much richer in manurial ingredients than the solid excreta. The relative composition of the solid excreta and the urine will be best illustrated by quoting some experiments carried out by Wolff on this subject. The experiments were carried out with two pigs nine and a half months old, and each 121.9 kilogrammes (a kilogramme is equal to about 2-1/4 lb.) in weight. The first consumed daily 1000 grammes of barley, 5000 grammes of potatoes, and 2572 grammes of sour-milk. The second one consumed the same quantities of potatoes and sour-milk as the first, and 1000 grammes of peas. The following table gives the results of excreta and urine daily voided, in grammes:—

NOTE VI.(p. 236).

Manurial Constituents in 1000 Parts of Ordinary Foods.

Based on Lawes and Gilbert's Analyses.

(Warington's 'Chemistry of the Farm,' p. 139.)

NOTE VII. (p. 241).

Analyses of Stable-Manure, made respectively with Peat-moss Litter and Wheat-straw (by Bernard Dyer, B.Sc.)

NOTE VIII. (p. 242).

Analyses of Bracken (by J. Hughes, F.C.S.)

NOTE IX. (p. 244).

Analyses of Horse-Manure.

For a fuller discussion of this question, the reader is referred to Heiden's 'DÜngerlehre,' vol. ii. p. 185, and also to Storer's 'Agricultural Chemistry,' vol. i. p. 575. The statements in the different text-books as to the quantity of manure produced by the horse are such as naturally to perplex the student. This discrepancy is due, however, to the different methods adopted by different writers of calculating this amount. The subject is further discussed in the footnote to p. 252. The following analyses of horse-manure may be valuable for reference. They are taken from Storer's 'Agricultural Chemistry,' vol. i. p. 496:—

NOTE X. (p. 247).

The Nature of the Chemical Reactions of Ammonia "Fixers."

For the student, the exact nature of the chemical reactions taking place may be of interest.

In the first place, it must be distinctly understood that the form in which ammonia escapes from the manure-heap is not, as is so commonly erroneously stated in agricultural text-books, as "free" ammonia. Whenever ammonia is brought into contact with carbonic acid, carbonate of ammonia is formed. When it is remembered that carbonic acid is by far the most abundant of the gaseous products of the decomposition of organic matter, it will be at once seen that free ammonia could not exist under such circumstances.1. In the case of hydrochloric acid, the following chemical equation will represent the nature of the reaction—

2. In the case of sulphuric acid, the equation will be—

3. With gypsum (CaSO₄)—

4. With copperas (FeSO₄)—

5. With sulphate of magnesia (MgSO₄)—

Reference has been made to the fact that magnesium sulphate may probably not only fix the ammonia, but the phosphoric acid. When magnesium sulphate, soluble phosphoric acid, and ammonia are brought in contact with one another, the double insoluble phosphate of ammonium and magnesium (MgNH₄PO₄6Aq) is formed. While such a reaction is possible, it is highly improbable that it takes place to any extent. The double phosphate is a crystalline salt which only separates after a considerable time, and in the presence of a large excess of ammonia.

NOTE XI. (p. 250).

Analyses of Cow-Manure.[181]

NOTE XII. (p. 259).

Composition of Fresh and Rotten Farmyard Manure (Voelcker).

Composition of fresh manure, composed of horse, cow, and pig dung, about fourteen days old:—

Composition of the whole ash:—

Composition of rotten dung, six months old, is as follows:—

Composition of the whole ash:—

NOTE XIII. (p. 263).

Comparison of Fresh and Rotten Manure (Wolff).

NOTE XIV. (p. 263).

Lord Kinnaird's Experiments.[182]

"Lord Kinnaird has given the particulars of a very careful experiment. He tried to test the comparative value of manure kept in an open court with that kept under cover. He selected the same kind of cattle, gave them the same kind and quantity of food, and bedded them with the same kind of straw. A field of 20 acres of uniform land was selected. This having been equally divided, 2 acres out of each 10 gave the following results:—

Potatoes grown with Uncovered Manure.

Potatoes grown with Covered Manure.

This shows an increase of about 4 tons of potatoes per acre with the covered manure.

"The next year the weather was wet, grain soft and not in very good order, but the following was the amount of produce:—

Wheat grown with Uncovered Manure.

Wheat grown with Covered Manure.

NOTE XV. (pp. 231, 264).

Drainings of Manure-heaps.

The importance of not separating the liquid portion from the solid portion has already been pointed out in dealing with the composition of the solid excreta and the urine. These two constituents of the manure are complementary to one another, and the value of farmyard manure as a general manure is very much impaired if the liquid portion is not applied along with the solid. In one important respect do the drainings of manure-heaps differ from urine—that is, in the percentage of phosphates they contain, the latter being practically devoid of phosphoric acid.

The following is an analysis of drainings from a manure-heap (Wolff):—

NOTE XVI. (p. 270).

Amounts of Potash and Phosphoric Acid removed by the following Rotations from a Prussian Morgen (.631 Acre).

NOTE XVII. (pp. 253, 254).

Composition of Farmyard Manure (Fresh), (calculated by Sir John Lawes).

NOTE XVIII. (p. 232).

The Urine.

An important consideration we have omitted to take note of in the text is the quantity of the urine voided. It is this consideration that renders the urine so much more valuable than the solid excreta. In the case of a man it has been estimated that the urine voided is fifteen times as much, is twelve times as rich in nitrogen, three times in potash, and two in phosphoric acid, as the solid excreta (Munro). The relation of solid matter in the case of the farm animals is not exactly similar. The urine of the ox is about twice the weight of its solid excreta. Both the horse and the sheep, however, void as a rule more solid excreta than urine. Munro, in his work on 'Soils and Manures,' contrasts the composition of the urine and solid excreta of the different farm animals by the following statement:—

FOOTNOTES:

---