8 circular 5 6 3, u. s. department of agriculture 



Archer 



Although crops were grown at the Archer field station in 1913-38 

 the data for only 6 years are available for the present study, because 

 there were no soil-moisture determinations made in 1918 or after 1919. 

 In none of the 6 years was available moisture limited to the first foot. 

 As between 2 feet and 3 or more feet of wet soil the results in individual 

 years are not very clear cut, but much higher average yields were ob- 

 tained from the greater depth. 



North Platte 



Records covering an unbroken series of 28 years, 1907-34, are 

 available from North Platte. Better average yields were obtained 

 from 2 feet of moist soil than from 1 , but available water to the depth 

 of 3 feet or more in the spring assured much higher average yields 

 and a high degree of safety. On land cropped to wheat each year 

 the soil was wet in the spring to the depth of 3 feet in about 40 percent 

 of the years, but on summer-fallowed land that condition obtained 

 in all but 1 of the 27 years of record for that method. 



Akron 



Spring wheat has been grown on the Akron station each year 

 since 1908, but soil-moisture determinations in the spring are avail- 

 able for only 11 years, 1908-17, and 1921. The number of years is 

 small, and the data are not conclusive. 



Amarillo 



Amarillo offers data for 11 years, 1907-18. The location of the 

 station was changed in 1910, and no data for the present study were 

 obtained in that year. All yields were too low to encourage the growth 

 of spring wheat, but yields were generally better with 2 and 3 feet 

 of wet soil than they were with only 1 foot. 



RESULTS AT ALL STATIONS 



A summary of the study of the three methods of preparation of the 

 land at all stations is given in table 1 . The sums and averages in this 

 table are brought together and further totaled and averaged in table 

 2 . The average results at all stations are shown graphically in figure 2 . 



