8 BULLETIN 1094, U. S, DEPARTMEZSTT OF AGRICIJLTTJES. 



The most valuable evidence perhaps is that from the oldest block 

 of plats, which have a continuous record from 1906 to 1920, inclusive. 

 There are 14 plats of winter wheat in this block. Four of these are 

 cropped continuously to winter wheat by different methods, one is 

 on fallow in a 2-year rotation (or alternation of wheat and fallow) , 

 seven are in 4-year rotations, and two are in 6-year rotations con- 

 taining brome-grass or alfalfa. 



The land had been under cultivation for some years before the 

 experimental work was started. The experiments being started in 

 the spring of 1906, spring wheat was sown that year. Results with 

 winter wheat are available for the 14 years from 1907 to 1920, in- 

 clusive. The yields from the 14 plats and also the average yield of 

 the county for each year of this period are given in Table 5. The 

 14-year averages are shown at the bottom of the table. 



Table 5. — Yields of winter loTieat in Ellis County, Kans., and in 14 plats at the Fort 

 Hays branch station for the 14-year period from 1907 to 1920, inclusive. 











Yields per 



acre for the several plats and rotations (bushels). 







Continuous wheat. 



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 -eg 



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c^f- 





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 ^ 





03 . 



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o tT 



- s 



c3 m 







6t 



3S 







— o 



c3 o 







_-.c! 



»!=l 







^ a 





'- 5 



aS 



■^ m.§ 



(S-S 



g 



=3 



"ft 



"^•a 





— < 



^^ 



>s 





..P. 





p^ 



..o 



..o 



^"^'is 



-la 



>H 



M 



< 



M 



H 



fe 



6 



L^ 



lO 



05 



u 



ij^ 



to 









1907 



9 



11.7 



18.2 



13.6 



12.4 



11.2 



12.3 



9.3 



14.0 



12.3 



14.5 



7.0 



9.9 



7.8 



8.8 



1908 



14 



25.6 



23.3 



30.5 



28.1 



32.3 



29.2 



21.8 



(M 



23.2 



9.4 



11.7 



11.9 



11.3 



9.4 



1909 c.... 



6 



























































1910 



13 



20.5 



27.8 



39.8 



36.8 



42.5 



42.7 



22.5 



40.1 



30.9 



39.3 



35.0 



29.5 



23.3 



25.1 



1911 



2 







.3 



.3 



.6 



2.6 



5.2 



1.2 



1.6 



2.3 



2.3 



.5 



.6 











1912 



12 



2.3 



13.8 



20.1 



26.6 



29.2 



27.7 







4.S 



13.2 



10.1 



8.6 



13.9 



19.0 



12.9 



1913 



6 



.8 



2.3 



4.1 



8.4 



10.3 



16.4 



8.7 



6.8 



8.1 



4.6 



2.5 



8.1 



11.6 



6.5 



1914 



19 



20.6 



24.8 



25.3 



23.1 



21.6 



19.9 



19.8 



18.5 



23.5 



22.5 



21.4 



24.0 



19.9 



6.7 



1915 



11 



9.3 



13.1 



14.9 



13.9 



11.3 



17.5 



19.8 



21.3 



21.8 



20.4 



18.8 



20.7 



21.0 



19.7 



1916 



13 



8.7 



22.7 



27.6 



23.1 



33.8 



31.8 



28.8 



29.8 



33.8 



33.2 



31.5 



36.6 



34.8 



23.5 



1917 



2 







2.0 



2.6 







7.1 



3.3 



5.3 



1.5 



3.8 



1.7 



.3 



.3 











1918 



9 



9.7 



14.9 



14.4 



24.8 



35.8 



12.6 



4.7 



13.7 



12.0 



13.7 



10.7 



9.3 



9.4 



9.3 



1919 



9 



17.9 



16.8 



18.9 



19.8 



10.0 



13.5 



14.6 



11.0 



13.7 



12.7 



20.6 



24.7 



21.8 



20.3 



1920 



18 



19.9 



24.4 



26.0 



24.2 



37.0 



33.3 



30.9 



31.1 



32.6 



32.2 



27.8 



37.7 



30.0 



29.1 



Avge.. 



10.2 



10.5 



14.6 



17.0 



17.3 



20.3 



19.0 



13.4 



14.9 



16.5 



15.5 



14.0 



16.2 



15.0 



12.2 



a Plowed under for green manure, i Spring wheat by error, c All wheat on the plats destroyed by haiL 

 CONTINUOUS AND ALTERNATE CROPPING TO WHEAT FOR 14 YEARS.* 



Of these 14 plats the greatest interest attaches to the four that are 

 continuously cropped to wheat and the two on which wheat and fal- 

 low alternate. These have no rotation number but are designated as 

 A, B, E, and F, continuously cropped, and C and D, on which wheat 

 and fallow alternate. Plats C and D are located between plats B and 

 E in the field. Plat A is late plowed and harrowed twice immedi- 



< Since this manuscript was prepared the 1921 results have become available. They effect only minor 

 changes in the averages and do not change the conclusions derived from them. The season was relatively 

 unfavorable to wheat raised continuously without plowing, to late-faU plowing, and to wheat following 

 com and kafir. In the methods-of-faUow experiment the yield o f the late-plowed plat in the pair N-0 was 

 relatively low and that of the listed plat in the pair P-Q was relatively high. 



