28 
BULLETIN 648, U. S. DEPARTMENT OF AGRICULTURE. 
of cotton is not profitable on the light, sandy soils of this area. A 
similar tabulation based on the total amount of mule labor expended 
on cotton up to the time of harvesting the crop gave similar results, 
though slightly less pronounced. The results in this case were less 
pronounced because there is less difference in the practices of culti- 
vating the crop after planting than there is up to that time. Similar 
tabulations based on man labor gave less consistent results, since man 
labor is not so good a measure of the amount of tillage, owing to 
the differences in the number of mules used per team. Xo doubt 
different results would have been found on a heavier type of soil. 
RELATION OF AMOUNT OF FERTILIZER APPLICATIONS TO YIELDS, COSTS, AND 
PROFITS. 
To calculate the cost of production it was necessary to ascertain 
the cost per acre of the fertilizers applied to each crop. The data 
thus gotten permit an interesting study of the relative economy of 
the application of varying amounts of fertilizers on the principal 
crops. Using the cost per acre as a measure of the rate of applica- 
tion, since it is the only common measure for all of the fertilizer 
materials used, the effects on yields, costs, and profits have been 
tabulated for the principal crops, as shown in Table XII. The cost 
covers all classes of fertilizing materials applied, including stable 
manure, cottonseed meal, and commercial fertilizers, the last named 
representing the greater part of the costs. On none of the crops 
tabulated, except sweet potatoes, and possibly watermelons, was stable 
manure an important source of fertilizers. Approximately half the 
farms purchased the raw materials and did the mixing at home, 
while the others used ready-mixed fertilizers. Xo account has been 
taken of the residual effects of fertilizers applied to preceding crops, 
but these are reduced to a minimum in a region with such a light, 
sandy soil, heavy rainfall, and long growing season ; and in any case 
they tend to neutralize each other when a group of farms are con- 
sidered, as has been done in these tabulations. 
Table XII.- 
-Relation of cost of fertilizer application* to yields, costs, and profits 
(Bi-ooks County, Ga.). 
Crop. 
Cost of fertilizers per acre. 
Number 
of records. 
Average 
cost of 
fertilizer 
per acre. 
Yield 
per acre. 
Cost per 
crop unit. 
Profit or 
loss per 
acre. 
f %2 and less 
23 
56 
35 
13 
9 
7 
SI. 42 
3.00 
4.85 
6.78 
8.76 
11.32 
Pounds. 
a 263 
283 
293 
314 
383 
427 
$0,087 
.088 
.096 
.101 
.094 
.086 
$7. 45 
§2 to 84 
8.00 
Si to$6 
4.83 
$6 to $8 
4.18 
S8 toSlO 
9.15 
$10 and over 
11.00 
143 
4.32 
299 
.091 
7.04 
a Net lint. 
