TILLAGE AND ROTATION EXPERIMENTS AT NEPHI, UTAH. 11 
all vegetative growth, so that, in order to keep the fallow clean, some 
weeding was necessary two or three times during the summer. It 
seems probable that fall plowing turns under weed seeds and grain 
kernels, some of which lie dormant until they are brought to the 
surface again the next spring by replowing or disking the land. 
Thus the operation which is intended to destroy all growth induces 
further growth by bringing other seeds into a position favorable to 
germination. Their growth requires frequent weeding of the fallow. 
These extra operations were unnecessary on the spring-plowed plats, 
and consequently the cost of producing crops on these plats was reduced 
to a point substantially below that on the fall-plowed plats. 
The average cost of spring plowing was $1.93 per acre, while fall 
plowing cost $2.13. Replowing the fall-plowed land cost on an 
average $1.85 per acre, while double disking the fall-plowed land cost 
about 75 cents per acre, making an average cost of $1.30 and increas- 
ing the cost of fall plowing to $3.43. The subsequent weeding of the 
fall-plowed land cost about 25 cents per acre. This, added to the 
cost of plowing and replowing or double disking, makes the total cost 
of fall plowing $3.68, as compared with $1.93 for spring plowing, a 
difference of $1.75 per acre. These figures, of course, do not include 
the cost of cultivating the fallow, seeding and harvesting the crop, 
etc., which was the same on all plats and hence need not be con- 
sidered here. 
It has been shown that spring plowing has given an average yield 
of 1.7 bushels per acre more than fall plowing. The average market 
value of wheat at Nephi during the past four years has been 75 cents 
per bushel. Spring plowing, then, has yielded $1.28 more per acre 
than fall plowing. The extra income added to $1.75, the amount 
saved by spring plowing as compared with fall plowing, makes the 
difference in net return $3.03 per acre in favor of spring plowing. 
The fact that spring plowing at the substation was done as early 
in the year as possible must receive emphasis at this point. The land 
at that time was in good condition for plowing, and it turned over in 
excellent shape. Later plowing was found to be less desirable. For 
this reason it might be advisable for farmers in distributing their 
farm labor to plow enough in the fall to allow them to plow all the 
rest of their land at the proper time in the spring. This practice is 
followed by many of the more successful farmers in the vicinity of 
Nephi. 
# Depth of Fall Plowing. 
Previous to 1908 all of the eight plats used in the fall depth-of- 
plowing test were given treatment as nearly uniform as possible, 
being alternately fallowed and cropped to winter wheat. In the fall 
of 1908 four adjacent plats, 16A, 17 A, 18 A, and 19A, were set aside 
for this test. Alternate plats, 16C, 17C, 18C, and 19C, were added 
