8 MASS. EXPERIMENT STATION BULLETIN 290 



Plots 4, 7, and 9 were selected as check plots because they had not received 

 any nitrogen during the preceding years. Otherwise they had not been treated 

 alike and had yielded different weights of crops. Their records have been care- 

 fully compared to ascertain whether there were consistent differences in their 

 native fertility; but none could be discovered. Sometimes one plot has been the 

 best of the three and at others it has been the poorest. Plot 7 has been the 

 highest producer 12 times and the lowest 8 times; while Plot 4 has been highest 

 14 times and lowest 15 times; and Plot 9 highest 7 and lowest 10 times. Plot 9 

 may perhaps be considered nearest the average as a producer. 



On the whole, the choice of Field A as a reasonably uniform field has been 

 borne out by the successive harvests. 



The three plots which were chosen for the applications of ammonium sulfate 

 had an uneven start insofar as their records for the early years bear witness. 

 Plots 5 and 8 had each received ammonium sulfate, but otherwise had been 

 treated quite unlike and had borne unequal harvests. Plot 6 had been treated 

 unlike any of the others for three years and this will be shown by Director Goess- 

 mann's report for 1888. 



.... during the years 18S5, 1886 and 1887, the plat was ploughed, harrowed and treated with 

 the cultivator in the same manner and at the same time as the remaining plats. During that 

 entire period no manurial matter of any description was applied. The appearance of every descrip- 

 tion of vegetation was, as far as practicable, prevented by a timely use of the cultivator. 



At the beginning of the past season, after having produced no crop for three succeeding years, 



it was prepared in the same way and at the same time as the other plats No manurial matter 



was on that occasion applied to plat 6. The date of planting the corn, and the subsequent treat- 

 ment of the crop to the time of harvesting, was the same in all cases. The yield of fodder corn 

 upon plat 6 was the third lowest in the scale including all plats; .... It was also the poorest- 

 looking crop upon field "A" during the larger portion of the season .... Our observation in this 

 connection confirms the results of more recent careful investigations into older systems of agri- 

 cultural practice. Black fallow, as a rule, does not materially benefit the productiveness of an 

 exhausted soil 



These three plots had one thing in common in 1889, the first year of the new 

 series. They had deteriorated markedly from their yields in 1883. 



Plots 5 and 6 adjoined like Plots 1 and 2 and each had a check plot without 

 nitrogen beside it. Plot 8 was separated from the other two by a check plot and 

 had a check plot on the other side also. For years the individual yields of these 

 plots were erratic. Sometimes one of the plots would yield less than the plot 

 without nitrogen, which was beside it. Ultimately, the problem was solved. 

 Bulletin 204 of this experiment station is devoted to these three plots in com- 

 parison with those without nitrogen, but the data will be included in this study. 



Interest in fertilizers is centered primarily in their effects on plants, the 

 measure of which is the yield by weight or volume of the portions of plants that 

 have economic importance. The dearest presentation of a mass of data accu- 

 mulated over a long term of years from a variety of crops is acconi])lished l)y 

 grouping together the annual yields of one kind of crop and comparing the 

 relative effects of the different fertilizers season by season. 



Oats 



Oats constitute the first group of crops because oats in 1890 were the first 

 crop to follow the corn crop of 1889. Winter rye followed in 1891. Then in 

 1892 began a rotation in which soy beans alternated with oats for several years 



