34 BULLETIN 757. U. S. DEPARTMENT OF AGRICULTURE. 
the amount of horse labor expended on each, the machinery cost per 
acre is approximately the total cost divided by the total number of 
acres under cultivation on the farm. If a tractor is used for any 
operation, a separate charge should be made for this item. The usual 
prices charged in custom thrashing have been used: this covers all 
costs for the use of machinery in this operation, The use of the 
automobile is of undoubted benefit to the farm business on the aver- 
age farm; however, the automobile is used to a considerable extent 
for pleasure purposes, and although a number of farmers were found 
who were willing to make an estimate of the benefit that the car is 
to the farm business, not enough data are available to justify pre- 
senting figures in this connection. 
Under the item " Thrashing, per bushel " two figures are given for 
each crop, the first in each case being the average charge for the 
period 1911-1916. and the second, the 1917 charge. 
Since manure is utilized on many farms, a charge should be made 
against the crops for this fertilizer. It has previously been pointed 
out that, on the average, approximately 30 acres are covered with 
manure each year on the farm of 610 acres. Assiuning an annual 
application of approximately 10 tons per acre, this application is 
equivalent to 0.65 tons per crop acre. This distribution of the charge 
is justified, inasmuch as the benefits from the manure accrue for 
several years after application and the object is eventually to cover 
the whole farm. 
COSTS FOR 1917 AS COMPARED WITH PREWAR COSTS. 
In Table IX are shown the relative costs of the various items enter- 
ing into farm operation for the period 1911-1916 and for 1917. on a 
representative farm having a total acreage of approximately 610, 
with an organization and equipment that approaches the average very 
closely. 
It will be noted that there is an increase in the cost of every item, 
the increases being particularly noticeable in the case of seed for 
planting and in the value of machinery. The cost of * ; Labor per pro- 
ductive day of work " is determined by ascertaining the total cost of 
all hired labor by the clay or month, together with the labor done by 
the family at average rates, and dividing the sum of these by the total 
number of days of productive work done per farm per year. By pro- 
ductive work is meant that which is applied directly to an enterprise 
such as wheat production or stock raising, etc. All other labor, such 
as that necessary for the general upkeep of the farm, is considered 
as overhead expense, and is paid for in the labor by the day or month, 
or is pro-rated to the various productive enterprises. The irfcrease 
noted in the cost of a productive day's work corresponds to the in- 
crease in the cost of labor bv the dav or month as indicated, 
