the weather for a period of five months (from April to September) with the following results:

Tests at the Central Experimental Farm at Ottawa, Canada, with horse manure exposed to the weather

for six months showed a loss of one-third of the nitrogen, one-sixth of the phosphoric acid and one-third of the potash, while a corresponding sample that was protected from the weather lost only one-fifth of its nitrogen, and none of the phosphoric acid or potash.

Examples similar to these might be given indefinitely from American and European experiments, but it is

only necessary here to state that all of these experiments show great losses in the valuable constituents of the manure from exposure to the elements, the decrease in value amounting to from thirty to seventy per cent for periods of from three to twelve months. These losses vary with the climatic conditions and with the quality of the rations. During heavy rains, espe

The culvert across the road was built to keep the barnyard dry. The colored stream which runs through it tells a story of waste of plant food

cially if occurring in warm weather, the losses will be much greater than in dry or cold weather. The relative decrease in value is larger for manures produced from rations of high nutritive value. In other words the more valuable the manure the greater will be the percentage of loss from leaching. It is conservative to say that manure exposed to the weather for six months loses fully half its value.

Solid Excrement Loses Value by Leaching.-It is not the liquid excrement alone that is washed away by

the rains, for the solid excrement contains a certain amount of soluble plant food which is removed by leaching. In addition to this there are chemical changes taking place in the manure which are converting some of the constituents, which were originally insoluble, into forms that are soluble in water, and these may be carried away by the rains. Below are given the results of experiments at the New Jersey Experiment Station to determine the losses due to leaching when the solid excrement alone was considered.

Leaching Removes The Available Nitrogen.—The figures given in the above tables representing the percentage of loss of fertilizing constituents from the manure do not tell the whole story. The nitrogen in the portion removed by leaching is more valuable per pound than that which remains, because it is in a form more immediately available to the crop. This fact is strikingly shown in an experiment at the New Jersey Experiment Station in which two plots were treated

with quantities of fresh and leached manures which would give exactly the same amount of nitrogen. The results, stated in percentage of gain over a plot receiving no manure, are given below.

Open Yard Feeding a Wasteful Practice.-Upon a majority of the farms in America, perhaps, the cattle are fed during the winter in open lots, the manure not being hauled away until the following summer or fall, if indeed it is removed at all. This method of feeding presents ideal conditions for excessive losses from leaching, and it is safe to say that more than half the fertilizing value of the manure is lost where this practice is pursued. In the corn belt of this country for instance, large numbers of cattle are fed during the winter, and it is not unusual to see a large feeding lot covered to a considerable depth with manure which is spread out and exposed to the weather in such a way that the maximum effects of leaching must take place. There is no doubt that considered from the fertility point of view alone these farms would be better off if the corn were sold from the farm, and the stover all plowed under.

Losses Due to Fermentation.-There is another source of loss in stored manure that may be quite as

wasteful as leaching, i, e., what is known as "hot fermentation." Manure is very easily decomposed, and there is no doubt that decomposition begins almost as soon as the excrement is voided by the animal. The first evidence of decomposition or fermentation is the odor of ammonia that is noticeable in the barn, especially in the morning, if the stable has been closed dur

More tha half

ing the night. This is due to rapid decomposition of urea, a nitrogeneous substance found in the urine. Ammonia contains nitrogen, and when its odor is perceptible it is a sign that nitrogen is being given off into the air, and that the manure, therefore, is undergoing a loss of this valuable constituent. The early decomposition of the urea will not be so likely to occur if plenty of absorbing material is used.