WHEAT PRODUCTION ON DRY LANDS. 59 
The average frost-free period at Moro is 145 days; at Lind, 136 
_ days; and at Nephi, 111 days. 
The fall disking of stubble land plowed early in the spring for 
fallow decreased winter wheat yields at Moro, Lind, and Nephi. 
Disking stubble Jand in the spring before plowing increased yields 
at Moro and at Lind when the plowing was done as late as June 1, 
_ but did not increase yields when the plowing was completed by May 1. 
- Yields of winter wheat after fall-plowed fallow when the stubble was 
burned and when different quantities of stubble were turned under 
- were identical in a 6-year period at Nephi. 
Early spring plowing gave the highest yields of winter wheat at 
Moro. The average yields of eight tenth-acre plats plowed at dif- 
ferent times were: 
Setcemeons 
i — 
nt tee 
Bushels per acre. 
‘f pememuauranecertiy (ety) - ce 5 £52 hee ede ees = ee shee 27.5 
MErnnINeD PE CWEL) none) kD SS Se ns 2s Age ee be 20k 
cero powiio {pr Lyi 2. ee. 2 2 eee eee eee 30. 0 
ie ease pia wie (May Lj.) 22 2025 lil iste eee. 28. 2 
. Mama aaitiiner plowie (J une 1)2- 222 3-2 s ost 2.2). kee eee 24. 6 
The average yields of spring and winter wheat in a 4-year period 
_ at Lind were: 
Bushels per acre. 
RS ce ee eg Se ea ee. 
0 ETERS es es PS a a re 8.2 
pera es Dlawins- (March): . 2-2... 1. be ee Se te ee ee ne 10. 0 
Mepeearueeini Wea SPC Ail) 2 8 oe 10. 2 
Pamepemmer plowme (June)..... >... 2-22-22 -).- 1.2 ee 2 eee 8.2 
The average yields of Turkey winter wheat at Nephi, for a 6-year 
_ period from 1916 to 1921, inclusive, were: 
Bushels per acre. 
ee Dai SE a en me PL a he 24.5 
emnmreuemer ei semigitt 85 crs ean Sle Sig ee 24. 2 
Je DEE eee en a ee 20. 9 
PaeeePCY DHOWING <6 = oo. es eo 2k eed ee EG Sea eee 15. 4 
In depth-of-plowing experiments at Moro in the nine years, 1912 
and 1914 to 1921, inclusive, the average acre yield of eight tenth- 
acre plats of spring wheat and winter wheat plowed early in the 
spring 5 inches deep was 20.4 bushels, and the average yield of eight 
_ tenth-acre plats plowed on the same dates 10 inches deep was 21.3 
» bushels per acre. 3 
_ In depth-of-plowing experiments at Lind for the years 1918 to 1921, 
inclusive, the yields from 4-inch dry fall plowing were higher than 
from 6-inch dry fall plowing. On wet fall plowing the yields ob- 
tained from plowing 4 inches and 6 inches deep were identical. 
_ On early spring plowing (March) slightly higher yields were ob- 
_ tained from plowing 8 inches deep. On plowing done in April and 
June the yields obtained from plowing 4, 6, and 8 inches deep were 
_ practically identical. 
At Nephi the average yield of winter wheat in the 10 years between 
1910 and 1921 on land plowed 10 inches deep was 1 bushel per acre 
a than that obtained on land plowed 5 inches deep. The yields 
rom 10-inch plowing were as good as the yields obtained from subsoil- 
_ ing15to18inchesdeep. Plowing in the fall and replowingin thespring 
_ did not increase winter-wheat yields over those from one plowing. 
| Packing land with surface or subsurface packers after plowing at 
_ Moro did not significantly increase the yields of winter or spring 
_ wheat. On land plowed early in the spring slightly higher yields 
