28 



BULLETIN 648, XT. 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. No 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. No 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 applications to yields, costs, and profits 



(Brooks County, Ga.). 



Crop. 



Cost of fertilizers 



per acre. 



Number 

 of records. 



Average 



cost of 



fertilizer 



per acre. 



Yield 

 per acre. 



Cost r-er 

 crop unit. 



Profit or 



loss per 



acre. 







23 

 56 

 35 

 13 

 9 

 7 



$1.42 

 3.00 

 4.85 

 6.78 

 8.76 



11.32 



Povnds. 

 a 263 

 283 

 293 

 314 

 383 

 427 



$0. 087 

 .088 

 .096 

 .101 

 .094 

 .086 



$7. 45 





$2to$4 



8.00 





$1 toS6 



4.83 





$6 to $8 











SStoSlO 



9.15 







11.00 











143 



4.32 



299 



.091 



7.04 















a Net 



lint. 











