TILLAGE AND ROTATION EXPERIMENTS AT NEPHI, UTAH. 



13 



It will be seen from the above that during each year since 1908 

 four adjacent plats, each plowed to a different depth, have been 

 fallow and that since 1909 these four plats, with four alternates, have 

 been cropped or fallowed. This arrangement has afforded an oppor- 

 tunity each year to study soil moisture on the fallow plats and yields 

 on the cropped plats, as influenced by shallow plowing, deep plowing, 

 and subsoiling. 



MOISTURE CONTENT OF FALLOW. 



All of the fallow plats of each year were sampled at the beginning, 

 in the middle, and at the end of the season. Samples were taken to 



>4t^S??4<Sf 



Fig. 5.— Graphs showing the average percentage of moisture in the first 6 feet of soil at the beginning, 

 in the middle, and at the end of the fallow season, as found in the spring-plowing and fall-plowing 

 tests at the Nephi substation, 1909 to 1912, inclusive. 



a depth of 6 feet, and the moisture content of each foot section was 

 determined separately. Table IV presents the data collected from 

 1909 to 1912, inclusive, and shows the annual and average percentage 

 of moisture in each foot section of soil and the average of the 6-foot 

 section in April, June, and September. 



The data presented in Table IV show (1) that there was very little 

 difference in the soil-moisture content of these plats in the spring, 

 summer, or fall; (2) that all of the plats uniformly lost much of the 

 moisture of the first foot during the spring cultivation necessary to 

 rid the plats of weeds and volunteer grain and to prepare them for 

 the fallow season; (3) that the moisture below the first foot remained 



