2 BULLETIN 10, U. S. DEPAKTMENT OF AGRICULTURE. 
minimum of 47.6° F. occurring in January. The maximum tempera- 
ture recorded is 112° F., and 16° F. has been registered as a minimum. 
These extremes are exceptional, however. 
As a preliminary step in starting the experiments at Davis, a 12- 
in.ch well was sunk near the northeast corner of the tract and a 4-inch 
horizontal centrifugal pump, directly connected with a 7|-horsepower 
motor was installed, thus insuring a reliable water supply. Water 
was delivered to the various checks and field laterals through 8-inch 
galvanized-iron slip -joint pipe. When properly fitted together this 
was practically watertight, eliminating loss in transportation. 
Before starting each irrigation the discharge from the pump was 
measured over an 18-inch Cippoletti weir, and the measurements were 
used in computing the amount of water applied. 
IRRIGATION OF ALFALFA. 
Operations were started in 1907, and in the fall of that year the 
major portion of the tract was leveled for alfalfa irrigation. Border, 
rectangular, and contour systems of checks were used, and at the 
time it was intended to rely upon the open-ditch system of the 
Yolo County Consolidated Water Co. for water. The accompanying 
sketch (fig. 1) shows the s}^stem of checks and ditches installed, the 
acreage of each check, and its number, which will be used in future 
designation. 
During the whole of 1908 the land stpod idle. Early in March, 
1909, plats 1 to 28, 32, 33, 34, and the west half of 35, 36, and 37 were 
thoroughly disked, cross-disked, harrowed, and seeded to alfalfa, 20 
pounds of Utah seed per acre being used. A grain drill, with alfalfa 
attachments, was used which placed the seed at a depth of about 1 to 
1J inches in the soil, in rows 6 inches apart. A good uniform stand 
was obtained, and by the middle of May a 3-inch to 4-inch growth 
had been made. 
The following schedule for the season's irrigation was outlined and 
closely followed: 
Schedule of irrigation, 1909. 
Number of plat. 
Number of irrigations. 
Dates of irrigation. 
Depth of 
water 
applied. 
1 to 4 
No irrigation 
Inches. 
5 to 9 
1 early 
15 
32,33 
1 midseason 
July 14.. 
6.1 
10 to 15 
Hate 
14 3 
36 
1 very late 
10 6 
/May 31 
12.5 
2 late 
\August 10 
15.4 
/July 14 
7.8 
\ August 23 
7.0 
37 
(August 1 
9.4 
[early 
\ September 9- 
8.9 
Mar 29. 
12.5 
16 to 19 
3< m id'season 
July 13 
7 2 
[late ;.. 
August 23... 
7.0 
