BULLETIN 157, IT. S. DEPARTMENT OF AGRICULTURE. 



In the plowing experiments at the Nephi substation comparisons 

 have been made between spring and fall plowing; subsoiling, deep 

 plowing, and shallow plowing; also between deep fall plowing followed 

 by shallow spring plowing and shallow fall plowing followed by deep 

 spring plowing. Most of the experiments have been in progress since 

 1908, and enough data are available to warrant a rather fuU discussion 

 at this time. 



Fall and Spring Plowing. 



Since the test of fall and spring plowing was co mm enced in the 

 fall of 1908, four tenth-acre plats have been used, thus permitting 

 the practice of alternately cropping and fallowing the plats. The 

 use made of each plat in each year since 1908 is shown in Table I. 



Table I. — Use of plats at the Nephi substation for the years 1908 to 1913, inclusive. 



Plat. 



1908 



1909 1910 1911 1912 1913 



12 A... 

 )3A 

 15P . . . 



Winter wheat. 



do 



Fallow 



Fallow 



do 



Winter wheat- 



Winter wheat. 



do 



Fallow 



Fallow 



do 



Winter wheat. 

 do 



Winter wheat. Fallow. 

 do ; Do. 



Fallow Winter wheat. 



do Do. 



From 1904 to 1908 the plats were alternately fallowed and cropped 

 to winter wheat in the same manner indicated above. During these 

 four years all plats received practically uniform treatment, being 

 plowed in the fall and allowed to he until the spring of the following 

 year, when they were double disked and harrowed and then fallowed, 

 with normal treatment until seeding time in the fall. 



In the fall of 1908 plat 13A was plowed as usual, while plat 12A 

 was not plowed until the spring of 1909. During the summer of 

 1909 the plats received uniform treatment. In the fall of 1909 plats 

 15D and 16D were segregated as alternates to plats 12A and 13A in 

 this experiment. Plat 16D was plowed in the fall and left without 

 further cultivation until the following spring. Plat 15D was plowed 

 in the spring of 1910. Both plats were fallow during 1910 and 

 received the same cultivation. 



It will be noticed that during the last four years each of the plats 

 in this test has been fallow two summers and has produced two 

 crops of winter wheat, a total of four crops; that each year there have 

 been two fallow plats and two cropped plats; that one plat of each 

 pair has been plowed in the fall and the other in the spring; and that 

 subsequent treatment has been as nearly the same in all cases as 

 possible. 



In studying the relative value of spring and fall plowing, moisture 

 conservation, yield per acre, and cost of production have been used 

 as bases of comparison. 



