APPLICATION OF SCIENCE TO PLANT CULTURE. 



79 



The question whether corn can gather its own nitrogen has been 

 much discussed. Experiments bear emphatic testimony on this 

 point. It has failed to respond to nitrogen — it may respond but 

 not in proportion to the amount applied, when it would respond to 

 phosphate and potash. Complete fertilizers brought larger crops 

 than barnyard manure. 



The experiments of the four seasons bear almost "unanimous 

 testimon}' to two things : The corn was helped but little by 

 nitrogen in the fertilizers ; and it gathered a good deal from 

 natural sources. The increase of crop and of nitrogen in the crop 

 will appear more clearly if we look at it in another way. 



Or, estimating the results in dollars and cents : 



The only cases in which the largest rations were profitable were 

 in the experiments of Mr. Newton. 



The above calculations of pecuniary loss and gain of course 

 appl}' onl}' to those regions where corn is dear. But even at 

 these rates the nitrogen increased the crop enough to pay its costs 

 in only 38 trials out of 213. The pecuniary loss rose and fell 

 with the amount of nitrogen used. With mineral fertilizers 

 alone the crop gathered, by the above estimates, some 60 pounds 

 of nitrogen per acre. 



