Live Stock Breeders' Association. 247 



able use of commercial plant food by those who make and save and 

 use farm manure to the greatest possible practicable extent, but 

 it serves only to emphasize the tremendous loss to the country from 

 the waste that is permitted. 



The value of farm manure can be, and has been, determined 

 by two entirely different methods : 



First, the manure may be analyzed chemically to ascertain the 

 kinds and amounts of plant food it contains and its value then 

 computed from the cost of the same amounts of these plant food 

 elements if purchased in the world's markets in commercial form. 



Second, the manure may be applied to the land in a series of 

 soil experiments where a suitable crop rotation is practiced, and 

 its value determined by computing from the value of the increase 

 which it produces in the different crops. 



The amount of plant food contained in a ton of farm manure 

 varies considerably and depends largely upon four important fact- 

 ors, which are probably correctly ranked in the following order : 



1. The condition as to dryness. 



2. The kind of feed and bedding. 



3. The state of preservation. 



4. The kind of live stock. 



The plant food in a ton of manure varies with the dry matter 

 content. Thus, manure containing 85 per cent of water, is only 

 half as rich in plant food as the same manure after the water 

 content has been reduced by evaporation to 70 per cent. This may 

 seem impossible at first thought, but a careful consideration will 

 show that it is true. If the manure contains 85 per cent of water, 

 it can contain only 15 per cent of dry matter; whereas manure 

 containing only 70 per cent of water must contain 30 per cent of 

 dry matter. Very erroneous conclusions are frequently drawn re- 

 garding the comparative value of different manures because of ap- 

 parently small or moderate differences in water content. Average 

 fresh mixed cattle and horse manure with an ordinary amount of 

 litter, or bedding, contains about 75 per cent of water and 25 per 

 cent of dry matter. Thus, a ton of such manure contains 500 

 pounds of dry matter and 1,500 pounds of water. 



The plant food in a ton of manure varies greatly with the 

 materials used for feed and bedding. Thus, wheat straw contains 

 per ton about 10 pounds of nitrogen, 2 pounds of phosphorus and 

 17 pounds of potassium ; while clover hay contains about 40, 5 and 

 30 pounds respectively of nitrogen, phosphorus and potassium. At 

 12 cents a pound for nitrogen, 12 cents for phosphorus and 6 cents 



