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FACTORS AFFECTING THE VALUE OF
Importance of Barnyard Manure.—Barnyard manure is the oldest and is still undoubtedly the most popular of all fertilizers. It has stood the test of long experience, and has proven its position as one of the most important manures. The fact that the application of the excrement of animals to the soil results in increased crop production, is mentioned by the early Roman writers, and from that time to the present, the majority of farmers have placed their main reliance on this class of manures for maintaining the fertility of the land.
“A well kept manure heap may be safely taken as one of the surest indications of thrift and success in farming. Neglect of this resource causes losses which, though little appreciated, are vast in extent. Waste of manure is either so common as to breed indifference, or so silent as to escape notice.
"According to recent statistics there are in the United States . in round numbers, 19,500,000 horses, mules, etc., 61,000,000 cattle, 47,000,000 hogs, and 51,600,000 sheep. Experiments indicate that if these animals were kept in stalls or pens throughout the year and the manure carefully saved, the approximate value of the fertilizing constituents of the manure produced by each horse or mule annually would be $27, by each
head of cattle $20, by each hog $8 and by each sheep $2. The fertilizing value of the manure produced by the different classes of farm animals of the United States would, therefore, be for horses, mules, etc., $526,500,000 ; cattle $1,220,000,000 ; hogs $376,000,000 ; and sheep $103,200,000 or a total of $2,225,700,000.
“These estimates are based on the values usually assigned to phosphoric acid, potash and nitrogen in commercial fertilizers, and are possibly somewhat too high from a practical standpoint. On the other hand, it must be borne in mind that no account is taken of the value of manure for improving the mechanical condition and drainage of soils, which as subsequent pages will show, is fully as important a consideration as its direct fertilizing value.” (Farmers' Bulletin 192).
If it is assumed that one-third of the value of the manure is annually lost by careless methods of management, and this estimate is undoubtedly conservative, the total loss from this source in the United States is about $750,900,000; a loss the more unfortunate because practically all of it could be prevented.
Composition of Manure From Different Animals. -The manures produced by the various classes of animals differ greatly in their composition and in their physical properties. The table on the next page gives the average percentage composition of the fresh manures (including solid and liquid excrement) from the more common farm animals.
By reference to this table it is seen that the difference in the value of the manures as given is due, to a large extent, to the variation in the amount of water present in the excrement of the different classes of animals.
The moisture content also affects the physical properties of the manure. Manures containing large amounts of water are “cold manures”; that is they are manures which heat slowly because the amount of moisture present checks the fermentation. Sheep and horse manures are known as “hot manures," and the more rapid heating of these when compared with pig or cow manure is probably due to their lower water content. The difference in the kind and quality of the feeds given to the various animals also affects the quality of the manure, as will be shown later.
Amount and Value of Manure From Different Animals.—The figures given in the previous section show the comparative fertilizing value of the different animal excrements and are, therefore, of importance to one who is purchasing manures. For the farmer who
* This valuation is based on 15 cents per pound for nitrogen, and 5 cents for phosphoric acid and potash. This represents in round nuinbers the market price of these elements in commercial fertilizers at the present, time. All the valuations given in the following pages will be on the same basis.
produces manure to use on his own land, it is more important to know the total amount and value of the manure produced in a year by the different classes of animals. In the quotation above from Farmers' Bulletin 192 the approximate value of the manure produced per head by the ordinary farm animals is given. A fairer way to present the matter is to calculate the manure to the same live weight of the different animals. The following table compiled from Cornell Bulletin 56 appears in Farmers' Bulletin 192.
AMOUNT AND VALUE OF MANURE PER 1,000 POUNDS OF LIVE WEIGHT OF DIFFERENT ANIMALS
Amount Value Value per day per day per year pounds
dollars Sheep . . . . . . 34.1
7.2 26.09 Calves . . . . . 67.8
24.45 Hogs . . . . . . 56.2
37.96 Cows . . . . . . 74.1
8.0 29.27 Horse . . . . . 48.8
If the figures given in this table are accepted as representing normal conditions, it follows that, making proper allowance for the proportion of the different kinds of animals found on the ordinary farm, the sum of thirty dollars may be taken as the average value of the fresh manure from each 1,000 pounds of live weight. The use of this factor (thirty dollars per 1,000 pounds) will enable the farmer to calculate approximately what the nitrogen, phosphoric acid and potash in the manure produced on his farm would cost if purchased in commercial fertilizers, granting
that the manure is so managed as to prevent loss of its valuable constituents.
Value of the Manure Determined by the Ration.The total value of the manure produced by a given number of animals is dependent on the quality and quantity of the feeding stuff used in the ration. That the different materials used for feeding vary greatly in their fertilizing value is clearly shown in the following table, which gives the quantity of fertilizing materials in one ton of a few of the common feeding stuffs.
The figures given in the above table represent the fertilizing values of the different feeds, provided they are used directly as manures. It is evident that the