4 BULLETIN 10, U. S. DEPARTMENT OF AGRICULTURE. 
The midsummer irrigation of July 14 produced two very light 
crops and left the plants alive but growing very slowly at the end 
of the season. Before this first irrigation was applied the root 
system had time to penetrate well into the subsoil and receive full 
benefit from the irrigation after it was applied. 
The late and very late irrigations both produced one fair crop 
besides the first light crop cut in May, and at the end of the season 
all of the alfalfa had shown a vigorous growth, with no apparent 
effects from the early drought, indications pointing toward a good 
}deld in the spring. 
Two irrigations. — In the plats given one early and one late irriga- 
tion only a 2-inch growth was shown between the cutting in the 
middle of June and the irrigation on August 10. Following the first 
irrigation the alfalfa made a slight growth, but it was not until after 
the second application that a substantial growth was made, which 
produced one fair cutting in September. 
One midsummer and one late irrigation produced a fair cutting 
in September, followed by a second and much heavier crop early in 
November. At the time of this last cutting the stand was in very 
good condition, the plants being deep-rooted and sturdy. 
Two late irrigations of 9.4 and 8.9 inches, respectively, applied 
August 1 and September 9, produced two good crops, the first on 
September 7 and the last November 12, and at the end of the season 
these plats had not only produced the heaviest first-season yields, 
but contained the hardiest and best appearing plants. 
Three irrigations. — In these plats the first and heaviest irrigation, 
applied May 29, seemed to have little effect upon the stand aside 
from keeping it alive; but after the second application, on July 13, 
the growth was rapid ; and following the third application of August 
23 a heavy first-year crop was taken off October 12, and a second fair 
crop in November, and at the end of the season the plants seemed to 
be very well developed, indicating probable heavy yields the following 
spring. 
Late in November plats 35, 36, and 37 were all given a very heavy 
early-winter irrigation. This was waste water pumped onto the 
plats during the testing out of the pumping plant, and, all told, the 
water applied must have amounted to a depth of about 18 inches. 
This seemed to have a remarkable effect upon the stand and was 
directly responsible for a heavy yield with small amounts of water 
the following summer. 
Although no definite conclusions can be drawn from a single 
season's observations, nevertheless the results obtained point to the 
following facts : 
(1) Without irrigation spring-sown alfalfa is uncertain in Sacra- 
mento Valley, and under conditions of normal rainfall and moderate 
