By a simple exchange of products without any cash outlay the fertilizing value of the ration would have been increased $75.35, and consequently the manure produced would have been worth $60.28 more than that resulting from the use of the corn and timothy hay. The increase in value of the manure does not tell all of the story, for the total weight of food has been increased nearly one-third. Its actual feeding value has been increased more than one-third, due to the larger amount of proteid in the ration. It is well known that cattle require less weight per head of a narrow ration than of one that is more carbonaceous. This example is cited merely as a suggestion of the possibilities of exchange. A little careful consideration will show that such exchanges may be made of great practical value.

The value of manure is affected by the quantity of food given the animal as well as by the quality. Other things being equal the manure from animals fed liberally will be more valuable than that from those that are fed insufficiently. This is mainly due to the fact that the latter use a larger proportion of the nitrogen of the food and hence the percentage returned in the manure is smaller. Liberal feeding then produces richer manure.

CHAPTER XIII

LOSSES IN MANURE

Relative Value of Solid and Liquid Excrement.— The great possibilities of barnyard manure as a means of supplying nitrogen, phosphoric acid, and potash to the soil have been discussed at some length. While values equal to those mentioned may be realized by any farmer by the exercise of reasonable care, the fact remains that few even approximate these results with their present practices. Barnyard manure is a perishable material, and must be handled with care and intelligence to obtain its maximum value. As manure is handled on the majority of farms to-day it is doubtful if half its worth is realized. The greatest loss that is likely to occur is the waste of the liquid excrement through the use of insufficient bedding to absorb it. The urine is really the most valuable part of the excrement, and unless plenty of bedding is used the value of the manure will fall far below that given in the previous chapter. Apparently few people realize the importance of using plenty of litter, for it is not unusual to see barns constructed in such a way as to cause the urine to run off as rapidly as possible. Doubtless the reader has before now seen holes bored in the barn floor to keep the floor dry by draining off the liquid excrement. The following table gives the composition of the solid and liquid excrements:

The table shows that considered pound for pound the liquid excrement is more valuable than the solid, except in the case of the swine. As the relative weights of solid and liquid excrement produced by the animals are not given it does not show the real proportional value of the liquid and solid excrement produced from a given ration. Several experiments have been made to determine this point, and there is a wide variation in the results. It is perfectly safe to say, however, that of the total fertilizing materials found in the manure two-thirds of the nitrogen, and four-fifths of the potash are found in the urine, but practically none of the phosphoric acid. The solid part then contains only onethird of the nitrogen, one-fifth of the potash, and nearly all of the phosphoric acid. It will thus be seen that a little over half of the total value of the manure is in the urine. In the example mentioned in Chapter XII, if the liquid excrement had been allowed to run away the value of the manure would have been less than $900.00 instead of $2,094.00 as calculated.

This fact is presented graphically in the diagram which shows the distribution of the fertilizing ingredients in the manure produced from the assumed ration

DIAGRAM SHOWING DISTRIBUTION OF FERTILIZING

INGREDIENTS IN MANURE

Plant Food in Liquid Excrement More Available. -The above statement does not properly show the comparative value of the solid and liquid parts of the manure. The plant food in the urine is in a form that is soluble in water, and, consequently, much more readily available to the plants than that in the solid excrement. The solid excrement consists of the undigested portion of the food, and must undergo thorough decay before its fertilizing constituents become avail

able to the plants, so that while something more than half of the actual plant food is in the urine, the value of the urine is much greater than the dung, owing to the better condition of its plant food. The difference is due largely to the more available form in which the nitrogen exists in the urine.

That the difference in value of solid and liquid excrement is not wholly theoretical is shown very nicely by a New Jersey experiment. In this experiment two plots were treated with manure, in one case the solid excrement only was used, in the other the mixed solid and liquid excrement. Each plot received enough of the manure to supply exactly the same amount of nitrogen, and the other elements were added in excess. The results are stated in percentage of gain over a check plot that received no manure and are given below.

PERCENTAGE OF GAIN IN YIELD FROM MANURE

Solid ex- Solid & liquid crement only excrement

It will be seen that the yield from the same amount of nitrogen was very much larger from the mixed manure than from the solid excremént alone. As the total amount of nitrogen added was the same in each case, the experiment indicates that the nitrogen in the liquid excrement was much more readily utilized by the plant than was that in the solid excrement.

Manure is never so valuable as when perfectly fresh.