60 BULLETIN 1178, U. S. DEPARTMENT OF AGRICULTURE. 
were obtained at Lind during a 4-year period on land packed with a 
packer. On land plowed in April the yields at Lind also have slightly 
favored the plats packed after plowing, while on June-plowed plats 
the reverse was true. 
Frequent cultivation of the summer fallow at Moro resulted in 
higher average yields of winter wheat on fall-plowed land or on land 
plowed April 1 and May 1 than no cultivation of the fallow or one 
harrowing only. Where plowing was done as late as June 1 culti- 
vation of the summer fallow did not increase wheat yields. At Lind 
there were only slight differences in the yields from the summer 
fallow receiving immediate tillage as compared with delayed tillage. 
At Nephi more cultivation than that necessary to control weeds did 
not prove profitable on the average. 
Soil moisture and nitrate studies at Moro and Lind indicate that 
tillage practices have an important bearmg on the accumulation of 
nitrate nitrogen in the soil. The quantity of nitrate nitrogen in the 
soil greatly influences the habit of growth of winter and spring wheat 
and the chemical composition of the wheat kernel. 
Experiments to determine the effect on yield of harrowing winter 
wheat in the spring show that on the average this practice reduced 
yields at Moro and at Lind. At Nephi it did not have any effect on 
the average yield of winter wheat. 
In the date-of-sowing experiments with winter wheat at Moro in 
the years 1916 to 1921, inclusive, shghtly higher yields were obtained 
from sowing winter wheat about the middle of September or carly 
in October than on later dates. Yields of winter wheat were signifi- 
cantly decreased when it was sown as late as November 1. The most 
profitable rate of sowing winter wheat at Moro was with the drill set 
to sow 5 pecks per acre of treated seed, or approximately 1 bushel per 
acre of dry seed. With spring wheat the highest yields were obtained 
at Moro from sowing early in the spring at the rate of 5 pecks per acre. 
At Lind slightly higher yields were obtained from winter wheat 
sown early than from wheat sown midlate or late in the fall. No 
advantage, however, was found in sowing wheat in dry soil. Experi- 
ments to determine the best rate of sowing winter and spring wheats 
at Lind indicate that the most profitable rate for either is about 4 
pecks per acre. Higher yields of spring wheat were obtained at Lind 
from early sowing. 
In the rate-of-sowing experiments with winter wheat at Nephi the 
highest average yields were obtained by sowing at the rate of 6 pecks 
per acre when that was the highest rate used, and from 8 pecks per 
acre after that rate was added. | 
In an experiment to determine the effect on yield of sowing winter 
wheat at different depths, no significant difference was obtained at — 
Moro during a 4-year period from wheat sown 2, 34, and 5 inches © 
deep. The depth of sowing winter wheat had an important influence 
on stand, especially when the wheat was sown late. At Lind there 
was an advantage from the shallow seeding of winter wheat. Sowing 
spring wheat at a depth of 4 inches gave slightly higher yields at Lind 
than sowing 1 and 24 inches deep. 
In a spacing experiment at Moro the same quantity of winter wheat 
sown in rows 7 inches apart produced higher acre yields than when 
sown in rows 14 inches apart. 
C) 
