IRRIGATION AT UNIVERSITY FARM, DAVIS, CAL. 5 
climate not more than one-half of the stand can be expected to sur- 
vive through the summer. 
(2) Heavy spring irrigations, when followed by long periods 
throughout the summer without water, did not benefit alfalfa. Exam- 
ination of the root growth under these conditions shows that water 
applied to the little plants in the early spring produces a root growth 
outwardly along the surface of the soil rather than downward, and 
when this is followed by long dry periods, the soil drying out leaves 
the young plant stranded above the moisture zone. Far better results 
were obtained by delaying irrigation until the root growth was well 
established, and even until the little plants seemed to be stunted and 
suffering for moisture. Well-developed, deep-rooted plants mean 
heavier yields. 
(3) Late and very late summer irrigations tend to produce sturdier 
plants and heavier yields the following summer. 
(4) After the root growth is well established, the growth may then 
be forced by frequent and, if the soil will stand it, heavy irrigations. 
, DUTY OF WATER FOR ALFALFA, 1910, 1911, AND 1912. 
The investigations during the first year's growth of the alfalfa had 
naturally destroyed the uniformity of the stand, making it necessary 
to reseed the whole area. Early in March the ground was thoroughly 
disked, cross- disked, and harrowed to a depth of 2 inches. It was 
then reseeded, 20 pounds- of Utah seed per acre being drilled in at 
right angles to the seeding of the year before. This seed was brought' 
up by the early spring rains and at the time of the first cutting on 
April 21 a very uniform stand covered the whole area. 
The previous year's work had shown that the water supply from 
the ditch system was inadequate for experimental work, and the 
pumping plant was installed and used in all subsequent Avork, the 
ditch system being abandoned. 
The following schedule for irrigation was outlined and followed on 
all but three of the checks in 1910 and 1911 : 
Schedule of irrigation^ of alfalfa, 1910 and 1911. 
Number of plat. 
Area. 
Depth ©f 
water 
applied. 
Schedule. 
1,2, 3, 4 
Acres. 
0.822 
.536 
.293 
.652 
.960 
.920 
.920 
1.000 
.573 
1.000 
.513 
Inches. 
No irrigation. 
Do. 
9, 10, 11 
_ 
8,12 
12 
24 
30 
30 
30 
36 
36 
48 
48 
6 inches after first and second cuttings. 
8 after first, second, and third cuttings. 
7J after first, second, third, and fourth cuttings. 
3f inches one week after first, second, third, and fourth cut- 
tings; 3| inches before second, third, fourth, and fifth 
cuttings. 
1\ inches one week before second, third, fourth, and fifth 
cuttings. 
7,13 
22,23,24,25 
17,18,19,28 
20,21,26,27 
33 
6,14 
cuttings. 
9 inches after first, second, third, and fourth cuttings. 
12 inches after first, second, third, and fourth cuttings. 
Do. 
32 
5,15 
