84 MASS. EXPERIMENT STATION BULLETIN 204. 



History of Plots. 

 The plots on which the sulfate of ammonia has been employed were 

 laid out in 1883 as a part of the first experiment field prepared by the 

 late C. A. Goessmann after the founding of the State Agricultural 

 Experiment Station in 1883. During the first six years the field was 

 used as a soil test, and corn was grown every year. In 1889 the plans 

 were rearranged to permit a comparison of standard nitrogenous ferti- 

 lizers, which has continued to the present time. The experiments have 

 been described with more or less detail in the annual reports of the 

 Experiment Station, under the headings Field A, and Experiments with 

 Nitrogenous Fertilizers. The earher reports were prepared by the late 

 Director Goessmann, ^ and the later ones by Director W. P. Brooks. ^ 



Soil Conditions. 

 The surface of the field has a slight, uniform slope toward the east 

 and south. The soil and subsoil are a sandy loam classified in the soil 

 survey of the Connecticut Valley as Norfolk, but later reclassified as 

 Merrimac.^ At a depth of 4 to 5 feet, as shown by the excavation for 

 drains, the field is underlain by the boulder clay of glacial till. The 

 geological formation is that of a river delta,* and excavations for build- 

 ings in the vicinity of the plots have shown no stratification in the under- 

 Ij'ing earth, but irregular masses of coarse and fine material so hard and 

 compact as to require constant use of the pick in excavating. Although 

 the surface soil is quite uniform, there is considerable variation in the 

 depth to the till, which possibly causes some of the differences between 

 plots handled uniformly ahke. 



Fertilizer and Lime Treatment. 



The field is laid out in 11 plots of one-tenth acre each, separated from 

 one another by strips 5 feet in width. A drain of 2-inch tile runs length- 

 wise through the center of each plot at a depth of 3 feet, and empties 

 into a well formed of 24-inch tile, 4 feet deep, at the bottom of which runs 

 the main drain along the eastern border of the field. 



The plots compared in this report are numbered 4, 5, 6, 7, 8 and 9. 

 Sulfate of ammonia has been applied to 5, 6 and 8 at the rate of 225 

 pounds per acre, while 4, 7 and 9 have received no nitrogen since 1882, 

 and probably a number of years preceding that. 



During the preliminary soil test, 1883-88, plots 6 and 8 were unferti- 

 lized, while 5 received sulfate of ammonia. Since 1889 all the plots have 

 received per acre 80 pounds of available phosphoric acid in superphos- 

 phates, and 125 pounds of potash in potash salts. Plots 4 and 5 have 



1 Mass. Agr. Expt. Sta., Ann. Repts., 1883 to 1896, inclusive. 



2 Mass. Agr. Expt. Sta., Ann. Repts., 1897 to 1917, inclusive. 



s Soils of the United States. Bui. No. 55, Bureau of Soils, U. S. Dept. Agr., p. 158. 

 * B. K. Emerson. Geology of Old Hampshire County. 



