MA.NLUUAL VALUE OF FEEDING STUFFS 217 



as well as a producer, with two possible profits instead of one, while 

 his farm should lose little of its fertility. The farmer who grows and 

 sells grain, hay, and straw is selling a large amount of fertility, the 

 need of which will surely be apparent as time goes on and his fields 

 give smaller and smaller returns. Such a farmer is slowly but surely 

 mining phosphorus and potash from his soil, which can be replaced 

 only by some purchased material. 



Virgin soils as a rule contain great quantities of available fertility, 

 and the pioneer farmers in America, drawing upon Nature's store, 

 have given little consideration to how their crops are fed, and have not 

 realized that they are steadily' and often wastefully drawing on the 

 fertility which is their principal capital. The western farmer, when 

 marketing corn or wheat, or the southern planter, W'hen selling seed 

 cotton, considers he is selling labor and rent of land. Rarely does he 

 realize that he is also selling fertility, to replace which would cost a 

 considerable part of all the crop brings. Rather than to reckon the 

 value of his crop at the market price, he should recognize that its true 

 value when sold from the farm is really the market price minus the 

 value of the fertility which the crop removes from the soil. 



In Great Britain, Miiere many of the farmers are long-period tenants, 

 the manurial value of feeding stuft's is recognized by law. AVhen a 

 tenant vacates his leasehold he is paid for the manurial value of feeds 

 which he has recently purchased and fed on the farm, and, under cer- 

 tain conditions, for the manurial value of grain produced on the farm 

 and fed to stock. Similar provisions should be drafted into farm leases 

 in this country'. 



Composition and value of fresh manure. — Tho the value of the 

 manure produced by each class of animals varies with the nature of the 

 feed supplied, it is important to study the average composi|j,ori of 

 manure for each class, as given in the following table.^ 



Composition of one ton of average manure from farm animals 



Phosphoric 



Water Nitrogen acid Potash Value 



Per ct. Lbs. Lbs. Lbs. Dols. 



Horse manure 78 14 5 11 3.30 



Cow manure 86 12 3 9 2.74 



Sheep manure 68 19 7 20 4.74 



Pig manure 87 10 7 8 2.52 



Horse or sheep manure contains less water than that of cows or pigs, 

 and these are known as "hot manures" because their low water content 

 permits rapid fermentation, or heating, when stored. On the other 

 hand, the voidings of the cow and pig form "cold manures," the high 



2 Adapted from Van Slyke, Fertilizers and Crops, p. 291. 



