FIELD CROPS. 



135 



Improvemerit hy selection (p. 47). — This experiment, requiring several 

 years, was begun in 1893. 



Depth of plowing (pp. 47, 48). — Tlie yield of corn for 3 years on land 

 plowed from 4 to 12 in. deep was as follows : 



Yield of corn per acre from deep and shallow plowing. 



Dfci)tb of plotvinf 



4to4Jin. 



6in 



81u 



lOin 



12 m 



Bushels. 



49.3 



49.1 



"49.8 



*49.6 



246.7 



Bushels. 



52.9 



58.9 



'60.0 



2.59.7 



2 61.4 



1893. 



Bushels. 

 16.1 

 13.6 

 '17.1 

 2 17.0 

 217.5 



Average, 

 3 years. 



Bushels. 

 39.48 

 40.54 

 42.28 

 41.76 

 42. 01 



'Average of 3 plats. 2 Average of 2 plats. 



"The small variations in yield in 1891 are doubtless due to the fact that all the 

 plats had been plowed 8 in. deep in previous years." 



Depth of cultivation (pp. 48, 49). — On land plowed about 8 in. deep 

 the average yields per acre for 6 years were as follows: Cultivated 

 about 1 in. deep, 51.06 bu. ; about 2 in. deep, 50.09; about 3 in. deep, 

 48.73. In 1893 deep culture gave slightly better results than shallow. 



Rotation (pp. 49-51). — 



"On one series of plats only grain crops are grown. . . . The crops of this 

 series are corn, oats, and wheat. The same crops have been grown in rotation in con- 

 nection with clover and timothy on an adjacent series. The crops on both series 

 have been grown without any manure or fertilizers and fullj"^ harvested and removed 

 in every instance. The yields of corn on the two series for 1893, and the average 

 yields for the last 6 years, are as follows:" 



Yield per acre from 7-otative and successive cropping. 



Crops grown in rotation. 

 Grain crops only grown. 

 Gain from rotation 



1893. ^^-erage, 

 ' 6 years. 



BusheU. I BusheU. 



22.2 ■ 31.99 



15.1 27.46 



7.1 4.53 



The yields of another series of plats on which wheat and corn alter- 

 nated, with and without fertilizers, are tabulated. 



Be.sidual effect of stable manure (pp. 49, 50). — On land which has been 

 in com continuously since 1879 fresh stable manure was applied in 



1883 and 1884, the total quantity being about 50 tons per acre. Since 



1884 no manure has been applied. The yields on the manured plats 

 and on check plats not manured in 1883 and 1884 are given in the fol- 

 lowing table: 



Yield of corn per acre from manure applied in 1SS3 and 18S4. 



