24 EXPERIMENT STATION. [Jan. 



On the basis of increase as compared with the no-nitrogen 

 plots the relative standing for the diiferent fertilizers for the 

 twentj-three years is as follows : — 



Per Cent. 



Nitrate of soda, 100.00 



Barnyard manure, 78.78 



Dried blood, 73.85 



Sulfate of ammonia, 53.19 



Nitrate of soda, as in previous years, shows the greatest 

 average increase. The striking results obtained last year on 

 the no-nitrogen plots are not so ap])arent this year. In 1911 

 the yield on the no-nitrogen plots was 95 per cent, of the aver- 

 age yield on all the different nitrogen plots ; this year the no- 

 nitrogen plots are represented by 73 per cent. In commenting 

 upon the good showing made by the no-nitrogen plots last year, 

 Dr. Brooks said : — 



One of the most striking results of the past season was the relatively 

 large yield produced on the no-nitrogen plots. It amounts to about 95 

 per cent, of the average yield on all the different plots which have re- 

 ceived an application of nitrogen annually. This result, it will be 

 readily understood, was no doubt due to the fact that clover for three 

 years had' preceded the corn crop of the past year. The figures empha- 

 size in a most striking way the extent to which rotations including a 

 legume may be made to take the place of the use of nitrogen fertilizers. 



MUEIATE V. SUT.FATE OF PoTASII. 



Field B. 

 This is the twenty-first year of the experiment. The field 

 consists of five pairs of plots, numbered from eleven to twenty. 

 The odd plots (eleven, thirteen, etc.) have received annually 

 an application of muriate of potash, while the even plots 

 (twelve, fourteen, etc.) have received an application of high- 

 grade sulfate of potash. In addition to the potash the plots 

 have received annually an application of bone meal at the rate 

 of GOO pounds per acre. During the early period of the experi- 

 ment the potash salts were used in different amounts in differ- 

 ent years. For the last twelve years an annual application of 



