Pea-straw is estimated at $3.74 per ton. When the peas are not allowed to grow until dead ripe, and when the straw is carefully cured, it makes capital food for sheep. Taking the grain and straw together, it will be seen that peas are an unusually valuable crop to grow for the purpose of making rich manure.
The straw of oats, wheat, and barley, is worth from $2.25 to $2.90 per ton. Barley straw being the poorest for manure, and oat straw the richest.
Potatoes are worth $1.50 per ton, or nearly 5 cents a bushel for manure.
The manurial value of roots varies from 80 cents a ton for carrots, to $1.07 for mangel-wurzel, and $1.14 for parsnips.
I am very anxious that there should be no misapprehension as to the meaning of these figures. I am sure they are well worth the careful study of every intelligent farmer. Mr. Lawes has been engaged in making experiments for over thirty years. There is no man more competent to speak with authority on such a subject. The figures showing the money value of the manure made from the different foods, are based on the amount of nitrogen, phosphoric acid, and potash, which they contain. Mr. Lawes has been buying and using artificial manures for many years, and is quite competent to form a correct conclusion as to the cheapest sources of obtaining nitrogen, phosphoric acid, and potash. He has certainly not overestimated their cost. They can not be bought at lower rates, either in England or America. But of course it does not follow from this that these manures are worth to the farmer the price charged for them; that is a matter depending on many conditions. All that can be said is, that if you are going to buy commercial manures, you will have to pay at least as much for the nitrogen, phosphoric acid, and potash, as the price fixed upon by Mr. Lawes. And you should recollect that there are other ingredients in the manure obtained from the food of animals, which are not estimated as of any value in the table. For instance, there is a large amount of carbonaceous matter in the manure of animals, which, for some crops, is not without value, but which is not here taken into account.
Viewed from a farmer’s stand-point, the table of money values must be taken only in a comparative sense. It is not claimed that the manure from a ton of wheat-straw is worth $2.68. This may, or may not, be the case. But if the manure from a ton of wheat-straw is worth $2.08, then the manure from a ton of pea-straw is worth $3.74, and the manure from a ton of corn-meal is worth $6.65, and the manure from a ton of clover-hay is worth $9.64, and the manure from a ton of wheat-bran is worth $14.59. If the manure from a ton of corn meal is not worth $6.65, then the manure from a ton of bran is not worth $14.59. If the manure from the ton of corn is worth more than $6.65, then the manure from a ton of bran is worth more than $14.59. There need be no doubt on this point.
Settle in your own mind what the manure from a ton of any one of the foods mentioned is worth on your farm, and you can easily calculate what the manure is worth from all the others. If you say that the manure from a ton of wheat-straw is worth $1.34, then the manure from a ton of Indian corn is worth $3.33, and the manure from a ton of bran is worth $7.30, and the manure from a ton of clover-hay is worth $4.82.
In this section, however, few good farmers are willing to sell straw, though they can get from $8.00 to $10.00 per ton for it. They think it must be consumed on the farm, or used for bedding, or their land will run down. I do not say they are wrong, but I do say, that if a ton of straw is worth $2.68 for manure alone, then a ton of clover-hay is worth $9.64 for manure alone. This may be accepted as a general truth, and one which a farmer can act upon. And so, too, in regard to the value of corn-meal, bran, and all the other articles given in the table.
There is another point of great importance which should be mentioned in this connection. The nitrogen in the better class of foods is worth more for manure than the nitrogen in straw, corn-stalks, and other coarse fodder. Nearly all the nitrogen in grain, and other rich foods, is digested by the animals, and is voided in solution in the urine. In other words, the nitrogen in the manure is in an active and available condition. On the other hand, only about half the nitrogen in the coarse fodders and straw is digestible. The other half passes off in a crude and comparatively unavailable condition, in the solid excrement. In estimating the value of the manure from a ton of food, these facts should be remembered.