172 AGRICULTURAL EXPERIMENT STATION. [Jan. 



1. Field Experiment to ascertain the Effect of Dif- 

 ferent Combinations of Nitrogen — i. e., Sodium 

 Nitrate, Chili Saltpetre, Aivimonium Sulphate 



AND JNITROGEN-CONTAINING OrGANIC MaTTER, UNDER 



Otherwise Corresponding Circumstances — on 

 Rye (1891). 



Field A. 



The well-authenticated and unbroken record of this field 

 extends over more than twenty years. The systematic 

 treatment of the soil, as far as modes of cultivation and of 

 manuring are concerned, was introduced during the season 

 of 1883-84. The subdivision of the entire area into eleven 

 plats (one-eighth of an acre each) of a uniform size and 

 shape, one hundred and thirty feet long and thirty feet wide, 

 with an unoccupied and unmanured space of five feet in 

 width between adjoining plats, has been retained unaltered 

 since 1884. A detailed statement of the particular aim and 

 general management of our experiments, as well as of the 

 results obtained in that connection, from year to year forms 

 a prominent part of our contemporary printed annual reports, 

 to which I have to refer for details. 



The most conspicuous I'esull of the field experiinents carried 

 on upon Field A during the years 1884 to 1888 consists in 

 the very striking illustration of a marked deficiency of the 

 soil on trial on available potash, as compared with other 

 essential articles of plant food. 



Since 1889 the main object of observations upon the same 

 field has been to study the influence of both an entire exclusion 

 of any additional nitrogen-containing manurial substance 

 from the soil under cultivation, as well as of a definite 

 additional supply of nitrogen in different forms of combi- 

 nation, on the character and yield of the crop selected for the 

 trial. The treatment of the soil adopted in preceding years 

 favored this new project for field observations. 



Several plats which for five preceding years did not receive 

 any nitrogen compound for manurial purposes were retained 



