I have said that if the manure from a ton of straw is worth $2.68, the manure from a ton of corn is worth $6.65; but I will not reverse the proposition, and say that if the manure from a ton of corn is worth $6.65, the manure from a ton of straw is worth $2.68. The manure from the grain is nearly all in an available condition, while that from the straw is not. A pound of nitrogen in rich manure is worth more than a pound of nitrogen in poor manure. This is another reason why we should try to make rich manure.
[ CHAPTER XIII.]
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.