﻿BULLETIN 10, U. S. DEPARTMENT 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- 

 inch 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 system 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 stood 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 

 1| 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. 



1 to 4 . . 

 5to9.. 

 32,33.. 

 10 to 15 

 36 



20 to 23 

 24 to 28 



37 



16 to 19 



Number of irrigations. 



No irrigation. 



1 early 



1 midseason . . 



Hate 



1 very late . . . 



1 early, 1 late. 

 21ate 



2 very late.. 



{early 

 midseason. 

 late 



Dates of irrigation. 



June 5 



July 14 



August 10 



September 9 . 



/May 31 



\August 10 



/July 14 



\ August 23 



/August 1 , 



\ September 9. 



May 29 



July 13 



August 23.... 



Depth of 



water 

 applied. 



Inches. 



15.0 

 6.1 

 14.3 

 10.6 

 12.5 

 15.4 

 7.8 

 7.0 

 9.4 

 8.9 

 12.5 

 7.2 

 7.0 



