CROPS UNDER FALL IRRIGATION AT SCOTTSBLUFF. 5 



No attempt was made to conduct these experiments in definitely 

 established crop rotations. The principal feature in the sequence of 

 crops from year to year was that in most cases a cultivated crop fol- 

 lowed an uncultivated one. For example, plat 2 in each series grew 

 wheat in 1911, corn in 1912, and oats in 1913; and plat 11 in 

 each series grew beets in 1911, wheat in 1912, and corn in 1913. 

 The field on which these experiments were conducted was broken 

 in the spring of 1910, so that all of the crops grown in 1911 were 

 produced on virgin soil. The sequence of crops on the plats in both 

 series during the years 1911, 1912, and 1913 is shown in Table II. 

 Exactly the same sequence was used in Series VI as was used in 

 Series VII ; that is to say, for any given plat in Series VI in any one 

 of the three years the corresponding plat in Series VII in the same 

 year was planted to the same crop. 



Table II. — Sequence of crops in the plats in Series Viand VII, used for the fall-irrigation 

 experiments at the Scottsbluff Experiment Farm in 1911, 1912, and 191.3. 



Plat No. 



Year and crop. 



Plat No. 



Year and crop. 



1911 



1912 



1913 



1911 



1912 



1913 



1 





Potatoes . . 



Corn 



Beets 



Barley 



Wheat 



Oats 



Corn 



Beets 



Barley. 



Oats. 



Wheat. 



Beets.i 



Potatoes. 



Corn. 



Oats. 



Wheat. 



9 



10 



Oats 



Potatoes . . 



Beets 



Wheat 



Oats 



Potatoes . . 



Barley 



Beets 



Barley 



Oats 



Wheat 



Potatoes . . 



Beets 



Barley 



Oats 



Wheat 





2 



Wheat.... 



Barley 



Oats 

 Potatoes . . 



Beets 



Wheat.... 

 Barley 





3 



11 





4 



12 



Oats.i 



5 



13 



Wheat.* 



6.... 



14... 







15 



Corn.i 



8 



16 



Barley. 





1 These plats were used for a special experiment in 1913, and the yields of the crops are not considered in 

 this report. 



Table II shows that with the exception of plats 4, 9, and 15, an 

 intertilled crop (potatoes, corn, or beets) was grown in alternation 

 with either wheat, oats, or barley during the 3-year period. 



RESULTS OF EXPERIMENTS. 



A discussion of the cultural treatments applied and of the results 

 secured in the fall-irrigation experiments during the 3-year period is 

 given in the pages that follow. 



Defiance spring wheat was used in these experiments and was 

 planted with a press drill at the rate of 6 pecks per acre each year. 



In 1910 the land in both series was plowed during the first week in 

 September. Both series were harrowed and leveled after plowing. 

 On September 15 Series VI was irrigated. After the irrigation it 

 seemed advisable to harrow Series VI for the purpose of checking 

 evaporation, and in order to preserve uniformity both series were 



