Chapter 51

HORSE MANURE AND FARM-YARD MANURE.

The manure from horses is generally considered richer and better than that from cows. This is not always the case, though it is probably so as a rule. There are three principal reasons for this. 1st. The horse is usually fed more grain and hay than the cow. In other words, the food of the horse is usually richer in the valuable elements of plant-food than the ordinary food of the cow. 2d. The milk of the cow abstracts considerable nitrogen, phosphoric acid, etc., from the food, and to this extent there is less of these valuable substances in the excrements. 3d. The excrements of the cow contain much more water than those of the horse. And consequently a ton of cow-dung, other things being equal, would not contain as much actual manure as a ton of horse-dung.

Boussingault, who is eminently trustworthy, gives us the following interesting facts:

A horse consumed in 24 hours, 20 lbs. of hay, 6 lbs. of oats, and 43 lbs. of water, and voided during the same period, 3 lbs. 7 ozs. of urine, and 38 lbs. 2 ozs. of solid excrements.

The solid excrements contained 23½ lbs. of water, and the urine 2 lbs. 6 ozs. of water.

According to this, a horse, eating 20 lbs. of hay, and 6 lbs. of oats, per day, voids in a year nearly seven tons of solid excrements, and 1,255 lbs. of urine.

It would seem that there must have been some mistake in collecting the urine, or what was probably the case, that some of it must have been absorbed by the dung; for 3½ pints of urine per day is certainly much less than is usually voided by a horse.

Stockard gives the amount of urine voided by a horse in a year at 3,000 lbs.; a cow, 8,000 lbs.; sheep, 380 lbs.; pig, 1,200 lbs.

Dr. Vœlcker, at the Royal Agricultural College, at Cirencester, England, made some valuable investigations in regard to the composition of farm-yard manure, and the changes which take place during fermentation.

The manure was composed of horse, cow, and pig-dung, mixed with the straw used for bedding in the stalls, pig-pens, sheds, etc.

On the 3d of November, 1854, a sample of what Dr. Vœlcker calls “Fresh Long Dung,” was taken from the “manure-pit” for analysis. It had lain in the pit or heap about 14 days.

The following is the result of the analysis:

Fresh Farm-Yard Manure. Half A Ton, Or 1,000 Lbs.

Water 661.7 lbs. Organic matter 282.4 ” Ash 55.9 ” ------------- 1,000.0 lbs. Nitrogen 6.43 ”

“Before you go any farther,” said the Deacon, “let me understand what these figures mean? Do you mean that a ton of manure contains only 12¾ lbs. of nitrogen, and 111 lbs. of ash, and that all the rest is carbonaceous matter and water, of little or no value?” --“That is it precisely, Deacon,” said I, “and furthermore, a large part of the ash has very little fertilizing value, as seen from the following:

Detailed Composition of the Ash of Fresh Barn-Yard Manure.

Soluble silica 21.59 Insoluble silicious matter (sand) 10.04 Phosphate of lime 5.35 Oxide of iron, alumina, with phosphate 8.47 Containing phosphoric acid 3.18 Lime 21.31 Magnesia 2.76 Potash 12.04 Soda 1.30 Chloride of sodium 0.54 Sulphuric acid 1.49 Carbonic acid and loss 15.11 ------ 100.00

Nitrogen, phosphoric acid, and potash, are the most valuable ingredients in manure. It will be seen that a ton of fresh barn-yard manure, of probably good average quality, contains:

Nitrogen 12¾ lbs. Phosphoric acid 6½ ” Potash 13½ ”

I do not say that these are the only ingredients of any value in a ton of manure. Nearly all the other ingredients are indispensable to the growth of plants, and if we should use manures containing nothing but nitrogen, phosphoric acid, and potash, the time would come when the crops would fail, from lack of a sufficient quantity of, perhaps, magnesia, or lime, sulphuric acid, or soluble silica, or iron. But it is not necessary to make provision for such a contingency. It would be a very exceptional case. Farmers who depend mainly on barn-yard manure, or on plowing under green crops for keeping up the fertility of the land, may safely calculate that the value of the manure is in proportion to the amount of nitrogen, phosphoric acid, and potash, it contains.

We draw out a ton of fresh manure and spread it on the land, therefore, in order to furnish the growing crops with 12¾ lbs. of nitrogen, 6½ lbs. of phosphoric acid, and 13½ lbs. of potash. Less than 33 lbs. in all!

We cannot dispense with farm-yard manure. We can seldom buy nitrogen, phosphoric acid, and potash, as cheaply as we can get them in home-made manures. But we should clearly understand the fact that we draw out 2,000 lbs. of matter in order to get 33 lbs. of these fertilizing ingredients. We should _try to make richer manure_. A ton of manure containing 60 lbs. of nitrogen, phosphoric acid, and potash, costs no more to draw out and spread, than a ton containing only 30 lbs., and it would be worth nearly or quite double the money.

How to make richer manure we will not discuss at this time. It is a question of food. But it is worth while to enquire if we can not take such manure as we have, and reduce its weight and bulk without losing any of its nitrogen, phosphoric acid, and potash.