BAELEY IN THE GREAT PLAINS AREA. 9 
The remainder of the field is in rotations in which each plat is 
known by a rotation number and letter. On the field diagram the 
separation of the rotations is indicated by heavy lines. 
The movement of the crops in the rotation is in the direction from 
Z to A and from A back to the letter that marks the other end of the 
rotation. 
In figure 2 the diagram is filled out to show the cropping in 1914. 
The letters following the crop indicate the treatment given the ground 
in preparation for it, S. P. standing for spring plowed, F. P. for fall 
plowed, Fal. for summer tilled, G. M. for green manured, S. S. for 
subsoiled, L. for listed, and D. for disked. To illustrate: In 1914 
plat A of the 4-year rotation No. 91 was in corn on fall-plowed 
ground, plat B was in oats on disked corn ground, and plat C was in 
peas on fall-plowed land. This would be plowed under for green 
manure. Plat D was in winter wheat where peas had been turned 
under the year before. In 1915, A will be in oats, B in peas, C in 
winter wheat, and D in corn. 
COMPARISON OF CULTURAL METHODS ON THE BASIS OF COST. 
The methods under study vary a great deal in the labor involved 
and in the consequent cost of preparation. Table IV has therefore 
been compiled in order to show the average cost by the methods under 
study as determined from the data of eight of the stations having the 
most trustworthy records. An average of the records for 5| years 
at each station has been used in compiling this table. This is equiva- 
lent to a record of 44 years at one station. An accurate record has 
been kept of all the farm operations performed under the various 
methods under trial. These have been averaged for the eight stations. 
The amount of work required for some methods of treatment varies 
with the season and with the soil, and the expense of some operations 
varies with the soil. The amount of labor performed under each of 
the methods was neither more nor less than that which the man in 
charge believed to be necessary to bring about the results sought. 
In computing the costs of the various operations a fixed wage of 
$2 a day for a man and $1 a day for a horse was adopted. This 
may be above or below the actual labor cost in any particular locality, 
but it is believed to be a fair average and one that will afford a prof- 
itable market to the farmer for his labor. The time required for 
men and teams to cover a given acreage in each of the several farm 
operations obviously varies with soils and other conditions. The 
average shown in Table II has been determined from the actual ex- 
perience of a large number of men connected with these investigations, 
which experience has extended over a wide range of conditions and 
many years of time. 
87710°— Bull. 222—15- — 2 
