IS a EXPERIMENT STATION. [Jan. 



that the crops obtained on the different plots must now afford 

 a pretty clear index to the relative values of the different ma- 

 terials and combinations applied. That this is the case is still 

 further indicated by the fact that the results during the past 

 three years in general have shown close agreement. It would 

 seem, therefore, that the main objects in view when the experi- 

 ment was planned have been realized, and for this reason 

 chiefly it has been decided to discontinue this branch of our 

 work in Concord. A similar line of experiments in progress in 

 Amherst will, however, be continued. A full account of the 

 experiments and a report on the results obtained both in the 

 field and in the investigations connected therewith in the chem- 

 ical laboratory will be published later as a bulletin. The follow- 

 ing brief account and summary of results and conclusions will 

 be of interest : ^ 



The fertilizer experiments were planned with a view to ob- 

 taining answers to certain definite questions. Among these 

 questions several of the most important relate to the use of 

 nitrate of soda. These questions are as follows: 



1. What amount of nitrate of soda, if any, can profitably be 

 used in connection with a liberal application of fertilizers sup- 

 plying phosphoric acid and potash? The nitrate has been 

 applied in three different amounts in each of four different sets 

 of plots. These amounts are at the following rates per acre: 

 300, 450 and 600 pounds. 



The results from year to year and in the different sets of 

 plots have not been strictly concordant. Nitrate of soda, how- 

 ever, has not failed in any combination to produce a large 

 increase in the crop. In a considerable number of instances, 

 the minimum application, 300 pounds per acre, has given as 

 large an increase as any larger quantity, but a study of the 

 yields and of the conditions affecting all plots leads me to the 

 conclusion that on the light soils of the Concord asparagus 

 district nitrate of soda at the rate of 450 pounds per acre will 

 usually give a more profitable increase in the crop when used 

 in connection with materials supplying abundant potash and 

 phosphoric acid in available forms than any larger quantity. 



2. What amount of nitrate of soda, if any, can profitably be 

 used in connection with a moderate application of manure? 



