20 BEGINNINGS IN ANIMAL HUSBANDRY 



and permits the entrance of air and the growth of roots 

 through it more freely than occurs where no vegetable 

 mould is present. Interesting experiments conducted for 

 more than 70 continuous years on the same land, in England, 

 at Rothamsted experiment station, showed that wheat 

 grown on unmanured land yielded just about 12 bushels per 

 acre, while a yield of about 40 bushels occurred where 

 stable manure was used. A ton of average stable manure is 

 considered to contain about $2.50 worth of plant food. 

 Professor Roberts has figured* that the average value of the 

 manure produced by a cow each day is eight cents, while 

 that of a horse is worth about a half cent less. The value of 

 stable manure, however, depends upon the feed the animal 

 gets. Feed rich in grain makes a more valuable manure 

 than that from hay only, and so will return more fertility 

 to the soil. 



The animal is a machine for changing coarse into fine 

 material. The ideal kind of farming combines the growing of 

 grass and grain and the feeding of these to the animals of 

 the farm. These raw crops are thus converted into 

 concentrated and high priced products, as represented in 

 meat, milk, butter, cheese, or breeding stock. A large per- 

 centage of the food consumed returns to the farm to keep 

 up its fertility. Some forms of stock farming remove but very 

 little of the actual soil fertility. One reason why dairy- 

 cattle farming meets with so much favor is because of the 

 small amount of fertility sold from the farm in milk or 

 butter. Professor Vivian states* that the fertilizing value 

 of a ton of butter is but 44 cents, and that 5000 pounds of 

 milk contain but $4.89 worth of fertility. As much as 80 



*Bulletin 56, Cornell University experiment station. 

 tFirst Principles of Soil Fertility, 1908, p. 120-121. 



