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Lot I was twice that of Lot II, there is very little difference in the value per ton, due to the fact that the weight of excrement produced in the first case was nearly twice that in the latter.
Effect of Bedding on Value of Manure.—The factors just discussed are those which affect the value of the excrement. The term barnyard manure as it is generally used includes the excreta and the litter or bedding used to absorb the urine. The following table gives the composition of some of the materials used for bedding
FERTILIZING CONSTITUENTS IN ONE TON OF LITTER
Nitrogen Phos. acid Potash
pounds pounds pounds Wheat straw . . . . 9.6 4.4 12.6 Oat straw . . . . . 9.2
35.4 Clover straw . . . . 29.4
25.2 Sawdust . . . . . 4.0
14.0 Peat . . . . . . 20.0
It is evident that the total fertilizing value of the manure is the sum of the value of the excrement and the bedding, and the richer the bedding is in fertilizing constituents the more valuable will be the manure. The materials used for bedding are in most cases rather low in the elements of fertility so that the use of large amounts of bedding decreases the worth per ton of the manure, but in any case sufficient litter should be used to absorb all of the liquid excrement.
Calculating the Amount of Manure From the Ration.--It is often of great interest and importance to the farmer to be able to calculate approximately the amount of manure that will be produced from the materials fed to his animals, as well as its value. Various estimates of the amount of manure produced by the different classes of animals have been made from time to time, but it will be much more satisfactory to use the ration as a basis for calculation. The total weight of manure may easily be computed in this way
and the figures derived are remarkably close to the average results as determined by experiment.
It has been stated that 50 per cent of the dry matter present in the ration is recovered in the excrement. Experience has shown that the least amount of bedding that will absorb all of the urine excreted by the animal must contain dry matter equal to 25 per cent of the dry matter in the feeding stuffs used. Hence, if the assumption is made that just sufficient bedding is used to absorb all of the liquid excrement it is seen that the manure (excrement plus bedding) contains 75 per cent as much dry matter as was contained in the ration. According to the table on page 115, mixed farm manures contain on the average 75 per cent of water, or only 25 per cent of dry matter, so that the 75 per cent of dry matter mentioned above as occurring in the manure, must be multiplied by four to find the total of manure. This gives a result of 300 per cent of the dry matter in the ration for the weight of the manure produced therefrom. It will thus be seen that to calculate the amount of manure resulting from the use of any given food materials it is only necessary to multiply the weight of the dry matter in the ration by three. This method of computation may perhaps be made plainer by an example. Let it be assumed that a mixture of feeding stuffs is used which contains 1,200 pounds of dry matter. The excrement produced by feeding this ration would contain 600 pounds of dry matter. In order to absorb all of the urine voided by the animal, straw, or some other bedding material must be used in an amount large enough to supply 300 pounds of dry matter. Now, as the manure is composed of the excrement plus the bedding it follows that the manure contains 900 pounds of dry matter. Only 25 per cent. of the manure is dry matter, so that the 900 pounds of dry matter in the example represents one-fourth of the total weight of the manure. The manure, therefore, weighs 3,600 pounds, which is just three times the dry matter that was present in the ration assumed.
ing the dry matter in the ration by three holds true, of course, only when the theoretical amount of bedding is used. In actual practice the farmer uses all of the bedding materials he has at hand even though in excess of the amount required to absorb the urine, and it is generally considered advisable to do so, for the bedding materials decay much more readily when mixed with the excrement of animals. In the best farm practice where the greatest possible use is made of all substances suitable for feeding there is seldom an excess of bedding materials. In case more litter than the theoretical amount is used the method of calculation given above must be corrected by adding to the total, the weight of the bedding in excess of 25 per cent of the dry matter in the ration. If in the example, for instance, instead of using 300 pounds of straw 500 pounds had been used as bedding, the total weight of the manure would have been 3,800 pounds.
AMOUNT AND VALUE OF THE MANURE
PRODUCED ON A FARM
Value of Manure Little Appreciated.—The great value of barnyard manure as a farm resource is appreciated by very few farmers. Its importance is doubtless realized to a greater extent at the present time than ever before, but even now a large proportion of those engaged in agricultural pursuits seem to have little realization of the immense loss incurred through the waste of this important product of the farm. Indeed many farmers apparently look upon the manure as one of the necessary nuisances of a system of animal husbandry, and begrudge the time and labor required to remove it from the barn and feeding lot. Barns have been erected on the banks of swift running streams with the express purpose of emptying the manure into the creek, in order that it may be removed with the least possible expenditure of labor. While these cases are extreme the reader has only to look around him as he travels through the country to see practices which fall only a few degrees short of this in the matter of wastefulness, due either to lack of knowledge of the value of the manure or to an indifference that is even more lamentable than ignorance.
Manure From Fifty Cows. In order that the great fertilizing value of the manure produced on the farm may be more definitely shown as well as to make more