42 



BULLETIN 157, U. S. DEPARTMENT OF AGRICULTURE. 



Wheat after corn gave the highest yield obtained in 1909, while 

 wheat after fallow yielded better than wheat after either potatoes or 

 peas. The yields of 1909, however, were extremely low because of 

 excessive winterkilling. Consequently they would be practically 

 worthless if they were not relatively the same as those obtained in 

 later years. In 1910 wheat after fallow yielded much less than wheat 

 after any intertilled crop. In 1911 wheat after potatoes gave the 

 highest yield, while there was little difference in the yields of the other 

 plats. Wheat after fallow again gave the lowest yield in 1912 and 

 1913. A summary of the wheat yields obtained in this test for the 

 five years from 1909 to 1913, inclusive, is given in Table XLX. 



Table XIX. — Annual and average yields of winter vsheat obtained after corn, potatoes, 

 peas, and fallov;, at the Nephi substation, for the years 1909 to 1913, inclusive. 



Yield per acre of grain (bushels). 



1912 1913 



Average. 



Wheat after corn 



Wheat after potatoes 



"Wheat after peas 



Wheat after fallow . . 



6.50 

 2.50 

 2.16 

 4.66 



19.30 

 17.20 

 18.30 

 13.10 



28.50 

 32.10 

 29. *0 

 30.00 



18.80 

 18.70 

 17.80 

 14.70 



4.40 

 4.20 

 4.20 

 2.00 



15.50 

 14.94 

 14.39 

 12.89 



Table XIX shows that the average yield of wheat for five years 

 was less after fallow than after corn, potatoes, or peas. 



A summary of the total crop yields of all plats since the test began 

 is given in Table XX, where it will be noticed that plats 12B and 

 12C, wheat after fallow, have given the lowest total returns per acre. 



Table XX. — Summary of total crop yields from the intertillage and fallow rotation plats 

 at the Nephi substation, 1908 to 1913, inclusive. 





Total yields per acre. 



Years and plats. 



Wheat. 



Corn. 



Peas. 



Potatoes. 





Grain. 



Fodder. 



Seed. 



Hay. 



1909 to 1913: 

 12B 



Bus. 

 28.40 

 37.10 

 36.00 

 37.00 



36.66 

 35. 20 

 38.66 

 40.20 



Bus. 



Lbs. 



Lbs. 



Lbs. 



Bus. 



13B 



None. 



None. 



2.9 



1,240 

 40 



550 



Failure. 

 20 



None. 



Failure. 



95 



1,050 



34.50 



14B 



15B 



1908 to 1913: 



12C 



84.70 

 4.00 



13C 



14C 



15C 



None. 



None. 



17.5 



40 



1,420 

 630 



90 

 220 



None. 



225 



1,080 



35 



42.50 



7.35 



32.40 



Table XX shows that the wheat yields on the "B" series are 

 greatly in favor of the plats which produced an intertilled crop in 

 alternate years, the differences in acre yields varying from 8 to 9 

 bushels. In addition to yielding as much wheat as plat 12C, the 



