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 Nephi 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 
