BULLETIN 133, U. S. DEPARTMENT OF AGRICULTURE. 



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and the irrigation during the growing season was uniform in both 

 cases. 



Irrigation was applied to the plats in both series by the usual meth- 

 ods. The potatoes, sugar beets, and corn were irrigated by means 

 of furrows between the rows and the grain crops were irrigated by 

 the field-flooding method. The water applied to the different plats 

 was not measured, but irrigation was practiced in the way it is com- 

 monly done by good farmers in the locality. The water was allowed 

 to flow over each plat so long as the soil absorbed it readily. In 

 1911, the only year in which soil-moisture determinations were made, 



it was found that at the first irri- 

 gation, June 10, the soil on the fall- 

 irrigated land, Series VI, absorbed 

 the irrigation water very readily. 

 The soil was saturated to a depth 

 of about 18 inches, and a good sup- 

 ply of water penetrated to a depth 

 of 6 feet. Series VII, which was 

 not fall irrigated, required a longer 

 run of water in order to saturate 

 the upper 18 inches of soil, and 

 when this was done dry soil was 

 found at a depth of 24 inches. Af- 

 ter several attempts to apply addi- 

 tional water to Series VII and thus 

 put moisture in the lower depths, 

 the loss of water by run-off was so 

 great that the flow had to be 

 stopped. The results of the mois- 

 ture studies made in 1911 are dis- 

 cussed later in this bulletin. 



The crops used in these experi- 

 ments were wheat, barley, oats, 

 potatoes, sugar beets, and corn, 

 until 1912, and only two years' 



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Fig. 1. — Diagram of Series VI and VII on field H, 

 Scottsbluff Experiment Farm, where the experi- 

 ments in fall irrigation were conducted. 



Corn was not included, however, 

 results with this crop are available. 



The experiments were conducted in field H, Series VI and VII, 

 shown in figure 1. Series VI was fall irrigated each year and Series 

 VII received no fall irrigation. The plats used were one-tenth acre 

 in size. In 1911 there were on each of the series three plats each of 

 wheat, barley, oats, potatoes, and sugar beets. In 1912 each series 

 contained two plats of potatoes, two plats of corn, and three plats 

 each of the four other crops. In 1913 there were on each series two 

 plats of barley, two plats of potatoes, and three plats of each of the 

 four other crops. 



