172 TwENTY-FlBST BlENNIAL RePOM 



until such time as the natural supply could be made avail- 

 able. In none of our experimental work have we found 

 potassium to be the first limiting element. 



Granting, for the sake of argument, the need of 

 potash on all soils, the ordinary application of fertilizers 

 used in this State will not meet the demands of crops for 

 potash. The 2-8-2 formula is a standard mixed fertilizer 

 in the State, although many are sold containing even 

 smaller amounts of nitrogen and potash. Two hundred 

 pounds per acre is above the average application. A 

 fifty-bushel com crop requires about forty-three pounds 

 of potash. The four pounds of potash contained in a 

 200-pound application of this fertilizer would be suffi- 

 cient for an increase of less than five bushels of com 

 if the crop could get it all. But no one would contend 

 that a crop could get all of the four pounds applied. 



The amount of nitrogen in such an application is 3.3 

 pounds and is sufficient for an increase of only two 

 bushels of com if all of it could be used. Nitrogen is cer- 

 tainly a limiting element before potassium on most if 

 not all of our soUs. Yet it is generally present in fertiliz- 

 ers in less quantities than potash. I have yet to be con- 

 vinced that any increased yield produced is not due 

 chiefly to the sixteen pounds of phosphoric acid con- 

 tained in the above application, which is a fair proportion 

 of the twenty-six pounds required for a fifty-bushel com 

 crop. If this be the case, why pay $2.50 to $3.00 for 200 

 pounds of this mixture containing sixteen pounds of 

 phosphoric acid when $3.00 wUl buy 400 pounds or more « 

 of sixteen per cent acid phosphate, containing sixty-four 

 pounds of phosphoric acid? 



If a farmer is convinced from experience that it 

 pays to use a small amount of complete fertilizer to 

 give the crop a start, and such may be the case, he should 

 at the same time understand that it neither supplies any 

 considerable part of the nitrogen and potassium used by 

 the crop, nor does it contribute to the permanent fer- 

 tility of the soU. 



Surely no one wUl contend at this late day that a 

 farmer should buy nitrogen for ordinary farm crops. For 

 example, a fifty-bushel corn crop requires seventy-five 

 pounds of nitrogen. Four thousand five hundred pounds 



