Alfalfa Seed Yields 
13 
3. A favorable soil and moisture condition for alfalfa seed pro- 
iuction seems to be a sandy to sandy loam bottomland with a water 
table about six to eight feet below the surface. Under such con- 
ditions, after the alfalfa is once started, the water will rise by 
sapillarity, thus supplying the plants without irrigation with suffi- 
,cient water for good seed development. Such conditions are fre- 
quently very successful for producing good alfalfa seed yield. 
Sometimes a light irrigation is required in addition in order to insure 
'seed yields. Whether or not the irrigation is required depends on soil 
,and climatic conditions. 
4. Heavy adobe soils that are rather impervious to moisture 
produce desirable alfalfa seed yields where the moisture can be 
supplied at the proper time and in the proper amounts. Applying 
Uvater at the proper time and in proper amounts requires experience 
with different types of heavy soil. Some growers have reported 
Instances where five or six irrigations were necessary to produce 
! a successful crop of alfalfa seed on heavy adobe soil. 
5. Deep, loamy soils that are well adapted for prolific hay yields 
I are not, as a rule, suitable for alfalfa seed production. When an 
attempt is made to control moisture, the seed yields are usually 
uncertain and irregular. 
6. Under strictly dry land conditions without irrigation or 
natural sub-irrigation from an underground water table, alfalfa seed 
production is usually a flat failure, with the climatic conditions 
common to Colorado upland dry farming. On very favorable soils, 
with a rainfall of 18 to 20 inches, fairly good results in seed pro- 
duction have been secured. 
These rather indefinite conclusions have been drawn from^ the 
field observations. In order to get more definite results on the 
specific question, “What are the moisture requirements for alfalfa 
seed production,” several experiments have been tried by applying 
different amounts of water at different times on alfalfa produced 
for seed. 
^ The first experiment was tried on a uniform field of alfalfa that 
had been sown in rows. The soil was uniform. The field of alfalfa 
had been developed from a single selection. This made all conditions 
as nearly uniform as one could reasonably expect under field 
conditions. 
Fifty rows in the field were divided into five sections of ten 
rows each. The first section was left unirrigated. The second 
section had irrigation water run in small furrows. The water ran 
about twenty minutes. The third section had the water running in 
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