No. 4.] KEEPING UP FERTILITY. 101 



Here ]'8 twice as much increase caused by potash as by 

 nitrogen, and about four times as much as that caused by 

 phosphoric acid. These experiments have been scattered 

 all the way from the east to the extreme west of the State. 

 I shoukl not be justified in conchiding, from the results of a 

 single acre in Amherst, that corn fertilizers should gener- 

 erally contain so much potash, because potash has produced 

 a far greater eftect in the increase of the corn crop than 

 either nitrogen or phosphoric acid ; but in this case there 

 have been so many experiments with similar results that I 

 feel pretty sure that I am right. 



With rare exceptions the results have been similar to those 

 indicated by these figures, and in a majority of instances 

 still more favorable to the potash. The results for potatoes 

 have been of the same character, but less marked. In the 

 case of clover they have been decidedly in favor of potash. 

 I may remark here, though I shall refer to this again, that 

 for grass nitrogen appears to be the most important. I 

 must not, however, dwell longer upon this part of my sub- 

 ject. I have said enough to indicate that I do not believe 

 the best way to keep up the fertility of our farms is to buy 

 and use special fertilizers. Good crops have undoubtedly 

 been raised upon them, but I believe usually at an unneces- 

 sarily large expense for fertilizer, because of the excess of 

 phosphoric acid for which the buyer must pay. 



Reasons why Potash is Deficient. 



That potash, more frequently than phosphoric acid, is 

 relatively deficient in soils, is the natural result of known 

 causes. First, most farmers in beginning^ to use fertilizers 

 employed superphosphates, which contained no potash. 

 Other materials commonly used were fish, bones and Peru- 

 vian guano, the first two being entirel}-, the latter almost 

 totally, deficient in })otash. It is true that wood ashes were 

 somewhat used, l)ut the supply was small, and the soap- 

 makers often extracted most of the potash. I have shown 

 that the special fertilizers of to-day are most of them rich in 

 phosphoric acid and poor in potash, and many of you are 

 using phosphates entirely. Second, all of our important 

 crops take much more potash than ])liosi^horic acid from the 

 soil. Third, it is the potash to a far greater extent than the 



