EXPERIMENT STATION REPORTS. 217 



tlie crop producing power of the soil in this instance showing an increase 

 of 18%% over the next highest yield and 21% over the wheat and clover 

 rotation. This was doubtless due largely to the heavy root system pro- 

 duced which stored up considerable ])lant food in vegetable form, that 

 become available again soon after breaking. The better physical condi- 

 tion produced by the heavy sod doubtless had much to do with the in- 

 creased production. 



(5) While the ])lots in the first series which had been fallowed for 

 10 years, produced more than any of the other plots of the series, ex- 

 cept those which had been in orchnrd grass, when the averages of both 

 series are considered, the yields are considerably lower than after the 

 rotations including clover, the wheat and clover showing an increase of 

 1.32% above the yield after the fallow. This possibly has been due to 

 the manufacture during the summer season of available nitrates which 

 have been washed from the soil since no crop was permitted on the plots 

 to utilize them. 



In the second part of the experiment whicli was devoted to the test- 

 ing of commercial fertilizers all the plots were planted in unifonn crops 

 from 1891 to 1898 evidently with the original idea of securing data for 

 a preliminary comparison of the several plots. The cropping during 

 this period and the yields from the several plots, which will give some 

 idea of their relative fertility, are shoT\ai in Table VI. The only in- 

 stance during the eight years in which the several plots seem to have 

 been accorded a different treatment was in 1894 when commercial fertil- 

 izers were applied as follows : Plot 2, 10 loads per acre of manure ; 

 plot 4, 100 pounds per acre of dissolved bone; plot 14, 100 pounds per 

 acre of ground bone; plot 16, 50 pounds per acre of sulphate of ammonia; 

 plot 18, 100 pounds per acre of Homestead fertilizer; plot 20, nothing; 

 plot 22, 100 pounds per acre of muriate of })otash ; plot 24, 95 pounds 

 per acre of common salt ; plot 26, 15 bushels per acre of wood ashes ; 

 plot 28, 100 pounds per acre of Lister's Success fertilizer; j)lot 30, 100 

 pounds per acre of nitrate of soda; plot 32, 50 pounds per acre of 

 sulphate of ammonia. 



From 1899 to 1905 fertilizers were applied annually to the several 

 plots as indicated in Table VII. The mixed commercial fertilizer at 

 first used was a sugar beet special but this was later changed to another 

 of the same analysis, viz. : Armour's Fruit and Root Crop Special which 

 has a guaranteed analysis as follows: Nitrogen, 1.65%; available phos- 

 phoric acid, 8.00%; potash, 5.00%. During the seven-year period in 

 which the fertilizers were applied the plots were cropped lengthwise of 

 the series or across all the plots, with various crops in narrow strips, 

 vaiwing from about 22 feet to 44 feet in width largely according to 

 the number of strips. The available notes lioAvever do not indicate the 

 order of planting of these strips, or in all cases the exact width so that 

 it is impossible to determine the order of cropping of any portion of 

 the series, or to determine the yield per acre of any of the crops, or 

 to check up the data on a profit and loss basis. In Table IX is given the 

 yield per acre from the several plots in uniform cropping during 1906, 

 1907 and 1908, following the seven-year period during which the fertil- 

 izers were applied. Table X prepared by Director C. D. Smith gives 

 the total amount of nitrogen, phosphoric acid, and i)otash removed in 

 crops and applied in fertilizers from 1899 to 1905 inclusive. 



