No. 4.] MANURIAL PROBLEMS. 177 



and other expcrinuMits progressed, and it was shown that the 

 beneficial influence of wood ashes was attributable as much 

 to the lime as to the potash, this comparison was finally 

 eliminated from the experiment, so that as now conducted 

 all of the plots in the rotation are manured alike, except in 

 the substitution of the stable manure for the reeular corn 

 formula upon three of the plots. 



In some instances the rye crops failed in the earlier 3^ears 

 of the experiment on account of poor seed, which resulted 

 from the fact that the germinating power of the seed was 

 not first tested, so as to insure that seed of good quality 

 would be used. Aside from injury to the clover crops 

 due to occasional drought, Avhich could not of course be 

 avoided, the chief disappointments in connection with this 

 rotation in the earlier years were the failure of the clover, 

 and the very small grass crops. In this respect the results- 

 Avere nmch the same as in the two five-year rotations which 

 include grass. The causes for the poor results with clover 

 and grass have since been ascertained to have been the 

 acidity of the soil, which rendered the growth of clover and 

 timoth}^ impossible ; and the use of too little nitrogen and 

 potash in the formula for top-dressing grass. 



Prior to 1901 many of the grass crops amounted to only 

 from 1 ton to 2^ or 3 tons per acre. Two notable excep- 

 tions were the crops upon two of the plots in 189G, which 

 yielded 4.61 and 5.83 tons respectively. Beginning with 

 the year 1901, when the grass formula was changed, the six 

 subsequent yields recorded are: 5.12, 3.4, 3.8, 5.58, 4.18 

 and 3.98 tons respectively. It has thus been demonstrated 

 that far greater profit results from a more liberal manuring, 

 such as is provided for in the amended gi'ass fornmla given 

 elsewhere (see page 172), than by the use of the former one 

 (see page 171). 



The yields of Indian corn (shelled) by the same manuring 

 employed at the outset have risen from a minimum of 16 

 bushels to a maximum of 83 bushels ; the 3^ields of stover 

 have also risen from a minimum of 1.23 tons per acre to a 

 maximum of 4.05 tons. The potat<i crops have risen from 

 130.8 bushels in 1893, only one-half of Avhich Avere of 



