18 
BULLETIN 1340, IT. S. DEPARTMENT OF AGRICULTLTRE 
quantity. The water used was measured over a weir and all run-off 
was measured and deducted from the quantity passing over the 
weir. 
The relation between the total quantity of water applied exclusive 
of the rainfall and the yields 01 alfalfa, spring wheat, oats, and 
potatoes is shown graphically in Figure 9, in which the average of 
a large number of tests is given. 
On April 25, 1911, 6 tanks each containing about 1,000 pounds 
of soil, were seeded to alfalfa at the Nevada Agricultural Experi- 
ment Station. This experiment formed part of the cooperative 
irrigation investigations carried on for a number of years by the 
Bureau of Public Roads and the Nevada Agricultural Experiment 
Station. The soil used was alluvial in character, intermixed with a 
considerable proportion of sand and small rock fragments, and typi- 
k 1 
lL -2 
1 * 
WATER APPLIED 
CROP 
YIELD 
Inches in Depth on Land 
ALFALFA 
On Farm near 
Richf!eld,Utah.Soil, 
chiefly Sand and Clay. 
Tons per Acre 
70 60 50 40 30 20 10 
5 10 15 20 
2 
2-5 
5 
3 
2 
1 
3-6 
5-6 
5-6 
6 
2 
2 
2 
1 
SUGAR BEETS 
Sandy Gravelly Loam, 
underlaid with coarse 
Gravel, near Prwo, Utah . 
4-6-7 
7 
7 
3 
2 
I 
POTATOES 
On Black Loam Soil 
mixed with Clay. 
at Holiday, Utah. 
Bushels per Acre 
50 100 150 200 250 
B 
+ 
BpMBiBMi 9 
as 
- 
ffltt- 
4 
2-4 
4 
2 
3 
1 
OATS 
On Clay Loam Soi 7 
near Tooele, Utah. 
20 40 60 80 
Ha 
Fig. 8.— Relationship between amount of water applied and crop yield for alfalfa, 
sugar beets, potatoes, and oats as determined at various places in Utah in 1905 
cal of soil formations in the vicinity of Reno. Soil samples taken 
when the tanks vere filled had moisture percentages of 11.9 to 12.8. 
Tanks 3 and 4 received 4 light irrigations during the season, in 
which 3 crops were harvested; tanks 5 and 6, received 4 medium 
irrigations; while the soil in tanks 7 and 8 was maintained at a 
fairly constant moisture content by adding, at the time of the semi- 
weekly weighing, the quantity of water lost by transpiration and 
evaporation. This plan was believed best to insure vigorous plant 
growth. 
The experiment was continued through the season of 1912, with 
the results as shown in Figure 10. 
On April 23, 1913, the tanks used in growing alfalfa the two pre- 
vious years were seeded to Marquis wheat. As in the case of alfalfa, 
tanks 3 and 4 received relatively small quantities of water, tanks 5 
