TILLAGE AND ROTATION EXPERIMENTS AT NEPHI, UTAH. 43 



other plats on the "C" series have given good yields of the intertilled 

 crops. From these results it appears that the production of inter- 

 tilled crops had some effect on the soil which was beneficial to the 

 following wheat crop. It is difficult to determine the nature of this 

 effect, but that it was present can not be doubted. 



The intertilled crops were sometimes unprofitable, in some instances 

 total failures, but the losses thus accruing were offset by profitable 

 yields in more favorable seasons. The cost of growing these crops 

 was somewhat higher than the cost of maintaining fallow, but the 

 yields of the intertilled crops and the higher wheat yields following 

 made up for this difference in cost. It is quite impossible to deter- 

 mine with any great degree of satisfaction the relative value of these 

 rotations, since the total yields of some of the intertilled crops were 

 so small, and because the production of such crops on the dry lands 

 of the Great Basin is practically unheard of, there is no standard for 

 estimating values. Perhaps the greatest value that will come from 

 the results of the above experiment will be to point out the possibili- 

 ties of such a rotation and to encourage greater effort in the develop- 

 ment of better varieties of intertilled crops or better methods of pro- 

 ducing the varieties now used. 



SUMMARY. 



The Nephi substation is located in the Juab Valley, in the eastern 

 part of Juab County, in central Utah. The soil in this locality is 

 very deep. It ranges from clay to sandy loam. In the virgin state 

 it is covered with a dense growth of black sagebrush. 



The average annual precipitation in the Juab Valley during the 

 past 16 years was 13.40 inches. During the progress of the experi- 

 ments reported herein (1908 to 1913), the precipitation in 1908 and 

 1909 was above normal, while in 1910, 1911, 1912, and 1913 it was 

 below normal. The winter and spring precipitation is the heaviest 

 of the year. The rains of summer have been small and consequently 

 of little value to the growing crops. 



The average evaporation at the JSTephi substation during the six 

 months from April to September, inclusive, has been about 45 inches. 

 The average wind velocity for any one day has not exceeded 10 miles 

 per hour. Protracted hot winds are unknown. Only two months 

 of the year, July and August, have been free from frost. Normally, 

 however, there are from 90 to 100 days in the frost-free period, ex- 

 tending from about June 15 to September 15. 



Most of the experiments reported upon have been in progress 

 since 1908. A few are of longer duration, while some were begun 

 as late as 1911. The tests have dealt with stubble treatment imme- 

 diately after harvest; time and depth of plowing; cultivation of 



