234 SYSTEMS OF PERMANENT AGRICULTURE 



of clover would equal one ton of hay per acre. This will be recog- 

 nized as the " best " common system of grain farming followed in 

 past years in the heart of the corn belt. And not infrequently the 

 live-stock farming has been like unto it, except that the corn 

 stalks have been pastured before being burned or disked down, 

 the clover has been pastured the first fall, cut for hay the next 

 summer, and pastured again before plowing for corn, and 10 loads 

 per acre of rotted and leached manure have been applied occa- 

 sionally to the high places, where the land is getting thin and where 

 the clover fails to catch. 



Another most significant fact should be considered in this com- 

 parative study of grain farming and live-stock farming; namely, 

 that 1000 bushels of grain has at least five times as much food 

 value and will support five times as many people as will the meat 

 or milk that can be made from it. (Not more than one fifth of the 

 nitrogen consumed in the food of animals is retained, as a rule, in 

 the milk or other edible animal products, and the proportion saved 

 of carbonaceous food is usually still less.) 



In his American lectures on the " Agricultural Investigations at 

 Rothamsted, England, during a Period of Fifty Years," which 

 were published as Bulletin 22, Office of Experiment Stations, 

 United States Department of Agriculture, Sir Henry Gilbert 

 " summarizes the results of very numerous experiments " conducted 

 at Rothamsted with growing and fattening cattle, sheep, and swine. 

 From this summary we obtain the following data: 



DISPOSITION OF 100 POUNDS OF DRY SUBSTANCE IN FOOD CONSUMED 

 Summary of Rothamsted Feeding Experiments 



Thus, a large proportion of the food digested is destroyed by 

 the animal and must be exhaled or thrown off as carbon dioxid, 

 water, urea, etc. Of the small percentage of the food that is 



