22 CIRCULAR 4 21, U. S. DEPARTMENT OF AGRICULTURE 



on the farm. A few fields were divided into the required units, 

 and crops were grown on them in definite rotation. These fields give 

 continuous records of different crops and can be studied as rotations. 

 By far the most fields were used as units, and the crops grown 

 were changed from year to year according to the needs of the live- 

 stock. Corn was grown largely for silage, but in many years some 

 of the corn was husked. Sorgo was grown both for fodder and 

 silage. In nearly every year, however, some- corn was husked for 

 grain and some sorgo was grown for fodder. 



In most years all the staple crops were grown on some field 

 or other. While the individual fields do not furnish much in the 

 line of comparable information, the average yields from all fields 

 are valuable. 



The yields from fields were averaged in order to obtain repre- 

 sentative figures for the different crops. For example, the yield 

 for ear corn given in any particular year is the average production 

 from all fields where the corn was husked. The average yield of 

 sorgo fodder for any given year is the average of all fields on which 

 sorgo was harvested for fodder, except field 13, which was located 

 on soil much less productive than that of any other field and where 

 difficulty was experienced in obtaining a good stand of sorgo. In 

 some years only one or two fields were planted to a certain crop. 

 In another year it may have been grown on 8 or 10 fields. Exactly 

 the same fields may not appear in the average in any 2 years. As a 

 whole, the averages give very good indications of the yields that 

 may be expected over a number of years by farmers using good 

 production methods. 



Since the purpose was the production of feed for livestock, it 

 follows that the fields were devoted to five principal crops — corn, 

 sorgo, oats, barley, and alfalfa. All the yields of these field tests 

 are shown in comparison with the averages of all plots in table 8. 



