250 CROP GROWING AND CROP FEEDING 



the formula based on the composition of the tubers. The difference between 

 the two fertilizers was strikingly shown by the appearance of the vines, for 

 those upon the Long Island formula plats were one-fourth larger than those 

 receiving the other formula, and in at least one instance the vines were of a 

 darker green. The two fertilizers differed in the proportions of two ingredi- 

 ents only, the Station formula being richer in nitrogen and poorer in phos- 

 phoric acid than the Long Island formula, potash being the same in each. 

 The variation in effect of the two combinations seemed greatest where the 

 smaller quantities were applied, which may indicate either that the Station 

 formula did not, in small quantities, furnish enough phosphoric acid, or 

 that in large amount it contained an undesirable quantity of the nitrogen 

 compounds. In either case, if future experiments substantiate the results 

 of this trial, the claim that the composition of a crop should be the guide in 

 mixing special fertilizers will be discredited. As the best form of potash 

 the bulletin says that it has been thought, and has been supported by some 

 experiments, that the liberal use of the muriate of potash tends to lower the 

 percentage of starch and dry matter in the potato, therefore chemical analyses 

 were made of tubers from each plat and comparisons were made of those re- 

 ceiving potash in the two forms of sulphate and muriate, in hope that light 

 might be thrown on that question. Taking the average of 16 plats for each 

 manner of treatment, it was found that where sulphate of potash had been 

 used the potatoes produced more of both dry matter and starch than where 

 muriate had been applied. But the significance of these results was utterly 

 nullified by the fact that the tubers from the unfertilized plat adjacent to 

 those differently fertilized differed in the same way, and to almost exactly the 

 same extent, seeming to show that it was a natural difference in the soil of 

 the plats rather than the kind of fertilizer used. The muriate in our own 

 experience has always given the largest yield, and so far as table tests can go 

 of fully as good quality as those grown with the sulphate, which is the more 

 costly form. 



This fact is borne out by the results at the Cornell University Experi- 

 ment Station, where an application of 200 pounds of muriate of potash and 

 300 pounds of acid phosphate made 318.2 bushels per acre, and the same 

 amount of fertilizer with the potash in the form of a sulphate made 310.5 

 bushels per acre. On two other plats the difference was still greater, for the 

 plat on which the same amount of muriate of potash was used made 360.6 

 bushels per acre while the plat on which the sulphate was used made but 

 333.5 bushels. Potatoes that were cultivated thirteen times made a smaller 

 crop than those cultivated nine times, and it was evident that nine cultiva- 

 tions will give the better crop in an average season. Still, as the bulletin 



