16 



CIRCULAR 5 6 3, U. S. DEPARTMENT OF AGRICULTURE 



Table 3. — Annual and average yields of spring wheat by each of three methods when 

 the soil was wet to different depths in the spring at 15 field stations in the Great 

 Plains during the period 1907-38 — Continued 



MANDAN (MAIN FIELD), N. DAK. 



Year 



Plot A 



PlotB 



Plots C and D 



lfoot 



2 feet 



3 feet 



lfoot 



2 feet 



3 feet 



lfoot 



2 feet 



3 feet 



1915 



Bushels 

 30.5 



Bushels 



Bushels 



Bushels 

 32.1 



Bushels 



Bushels 



Bushels 



Bushels 



Bushels 

 39 3 



1916 





19.2 

 15.3 





18.5 

 14.8 

 15.3 







21.8 



1917 















17 2 



1918 





12.7 



7.5 











32.0 



1919 









5.3 







15 7 



1920 



1.5 

 1.8 





1.0 

 









9 5 



1921 .. .. 













3.5 





1922 - - 



19.5 

 8.3 

 21.5 



18.5 





12.2 



2.8 







29 



1923 . .-- - . 















14 2 



1924 







15.8 









29 3 



1925 





14.2 









31 2 



1926 



1.0 



22.2 









21.2 

 16.2 









9 



1927 













31.7 





1928 .- . -- - 



15.5 



~"~13.y 









22.8 



1929 --. - 





9.0 



4.2 



2.8 



21.2 









20 2 



1930 





10.2 









23 8 



1931 





13.2 











19.3 



1932 





26.0 

 









34.8 



1933 









 

 20-7 

 

 2.2 









5.3 



1934 



1.5 









5.5 

 19.3 





1935 



22.7 







4.0 

 10.8 













1936 















1937 









7.2 











6.0 









19.3 



















9.8 



12.7 



15.4 



8.9 



9.0 



16.2 



7.2 



15.0 



20.7 









6 



14 



4 



13 



8 



3 



1 



4 



19 





MANDAN (SOUTH FIELD), N. DAK. 









1915 . --- 





29.3 









30.4 

 17.8 







45.3 



1916 





15.5 











11.8 



1917 



7.3 





6.3 









13.8 



1918 

















3.8 





1919 





6.3 



5.8 





13.0 



1920 



















10.0 



1922 



17.5 











16.3 

 16.0 

 16.3 





1923 



5.0 

 • 13.3 

 10.0 

 



20.0 

 8.0 















1924 

















1925 















21 



1926 















2.3 





1927 













30.8 





1928 















24.3 



1929 _ 



5.2 















12.2 



1930 --- 



4.7 















14.7 



1931 



4.0 













9.0 

 21.8 





1932 



17.8 















1933 

















2.8 



1934 















1.0 







1935 



18.5 











14.3 























7.8 



11.3 



7.8 



3.2 







18.0 



15.9 



12.5 



16.9 







Number of years 



11 



7 



2 



2 



1 



3 



2 



8 



10 



HETTINGER, N. DAK. 



1912 





14.3 

 13.8 







12.0 







17.5 





1913 







10.7 



6.2 



29.3 







37.0 



1914 ... 



10.0 









10.0 





1915 



40.7 



""4 2 









37.5 



1916 







5.5 







4. 2 



1917 



5.2 

 7.5 

 





1.7 

 8.5 

 









16.8 



1918 















13.5 



1919 















10.5 



















Average. 



5.7 



22.9 



4.2 



9.4 



12.0 



5.5 





13.8 



19.9 







Number of years 



4 



3 



1 



6 



1 



1 







2 



6 



