450 ANNUAL, REPORT OF THE Off. Doc. 



1. Ill leaciiiug fresh luamire there are great losses of nitrogen and 

 potassium and moderate losses of phosphorus and organic matter, 

 tlie materials lost being carried away in the leach water. 



2. In fermentation and heating there are great losses of nitro- 

 gen and organic matter in volatile products Avhich escape into the 

 air, InU if no leaching occurs there is no loss of phosphorus or po- 



In an exact experiment conducted at Cornell "University, 4,000 

 pounds of ordinary manure from the horse stable, worth |2.74 per 

 ton for the plant food it contained, Avere exposed in a pile out of doors 

 from April 25 to September 22 (about five months), but at the end 

 of that time the total weight 'decreased from 4,000 to 1,780 pounds, 

 and that was worth only $2.34 instead of |2.74 per ton. In other 

 words, the value of this pile of manure was reduced from |.j.48 to 

 $2.()c; during the five months exjiosure. In another experiment ma- 

 nure exposed for six months lost 56 per cent, of its dry matter and 43 

 per cent, of its plant food value. In this case the fresh manure was 

 worth -11^2.27 a ton, v^hile the rotted manure Avas worth |3.01 a ton, but 

 the loss in total weight and plant food was such that for each ton 

 originally worth |2.27 there remained only |1.30 worth after six 

 months' exposure. 



The plant food in a ton of manure varies somewhat with the kind 

 of live stock. Thus, young, growing animals and animals giving 

 milk will retain a larger proportion of the nitrogen and phosphorus 

 than fattening stock, work horses or other mature animals. On the 

 other hand, it is well understood that the difference in value coin- 

 monlj' recognized and most frequently considered, as, for example,, 

 between sheep manure and horse manure, are due almost entirly to 

 the difference in Avater content. As a matter of fact, manure from 

 work horses or from fattening steers fed on clover hay and heavy 

 grain rations is fully as rich as sheep manure if both are reduced 

 to the same percentage of dry matter. Of course, sheep manure 

 containing only CO per cent, of water, is twice as rich as cattle 

 manure containing 80 per cent, of water. 



Average fresh cattle or horse manure, made from clover and tim- 

 othy hay and some grain, Avith sufficient straAv bedding to absorb and 

 retain the liciuid manure, Avill contain per ton of manure about ten 

 pounds of nitrogen, tAvo jiounds of phosphorus and ten pounds of po- 

 tassium, on the basis of 2.5 per cent, of dry matter. Computed at the 

 present market values for these elements — 15 cents a pound for 

 nitrogen, 12 cents for phosphorus and 6 cents for potassium — such 

 manure would be A^alued at ,|2.34 a ton. 



Some will argue that the plant food in farm manure is not so 

 readily aA^ailable and consequently should not be valued so highly 

 as that in commercial form, but experiments shoAV that Avheu a 

 series of years is considered the farm manure may be worth about 

 as much as the commercial materials on the basis of plant food con- 

 tent. Thus, at the Rothamsted Experiment Station, an application 

 of 14 tons of farm manure, furnishing, according to the above aA^er- 

 ages, about 140 pounds of nitrogen, 28 pounds of phosphorus and 140 

 pounds of potassium, j)er acre per annum, has maintained the yield 

 of wheat at 35.0 bushels per acre, as an average of fifty years; Avhile 

 an aA^erage yield of 36.9 has been maintained during the same years 

 by an application of commercial plant food furnishing 129 pounds of 



