THIRTY-SEVENTH ANNUAL CONVENTION. 163 



larger the proportion of untillable land in a farm, the more im- 

 portant it is that the tillable area be devoted to intensive systems 

 of cropping. In order to have the systems of farming on the 

 same basis, it is necessary to take a definite yield for each of the 

 crops raised. These are the same for all systems and no attempt 

 is herein made to exhibit phenomenal or impossible results as 

 the yield has been fixed as nearly as possible at the average pro- 

 duction per acre for the different crops on the better class of 

 farms of Illinois. Dairymen who have farms less productive, 

 or who for any reason get smaller yields, must scale down the 

 final results in proportion to the crops obtained, and those who 

 can produce greater yields should raise the results proportion- 

 ally. 



Showing Yields of Crops Raised, in Bushels, Pounds and Digestible 

 Nutrients Per Acre. 



Crop. Yield per Acre Digestible Nutrients. Total 



Amount Lbs. Prot.Tot'l Carbo. Total Fat Total per crop 



Oats (grain) . . . 



. 50 bu. 



1600 



147 



166 



757 



1375 



67 



80 



971 



1621 



Oat straw 



...1600 lb. 



1600 



19 





618 





13 





650 



Corn (grain) . 



. . 55 bu. 



3080 



240 



308 



2054 



3350 



132 



160 



2426 



3818 



Corn stover. . . 



2 T. 



4000 



68 





1296 





28 





1392 



Timothy hay. . . 



. 1% t. 



3000 





84 





1302 





42 



1428 



Clover hay.... 



• 2% T. 



5000 





340 





1790 





85 



2215 



Alfalfa hay. . . . 



4 T. 



8000 





880 





3168 





96 



4144 



♦Pasture 









160 





585 





45 



790 



From the foregoing table is derived the comparative value 

 of the four systems of cropping from the standpoint of the pro- 

 duction of food material for dairy purposes. The table below 

 shows the relative amounts of available digestible nutrients pro- 

 duced by each of the four systems. 



System No. 4 produces 2% times as much as System No. 1. 



The total amount of digestible nutrients produced on a 160- 

 acre farm, and available for cows under each of the four sys- 

 tems, after allowing eight acres for roads, yards, etc., is , there- 

 fore, as follows : 



