A field of alfalfa seeded in rows. It is easy to see the dry spots. Around these dry spots 
there was a range of moisture, varying from too dry for production up to too wet, yet 
there was no apparent evidence of a zone of good seed setting anywhere between these 
two ranges. 
Colorado Experiment Station 
influences affecting seed production. But as these are beyond the ^ 
control of man, it is apparent that seed production must be achieved 
by adapting the alfalfa or alfalfa growing conditions to meet the 
climatic conditions. This line seems to offer the most feasible promise 
in future investigations of the alfalfa seed problems. 
i 
SOIL FERTILITY AND ITS EFFECT ON ALFALFA SEED j 
PRODUCTION 
Investigation of the effects of different fertilizers on alfalfa seed j 
production has been omitted or overlooked, probably because of the 
many successful seed yields under conditions where no special soil | 
fertility was provided. 
If a record of alfalfa seed yields in the Arkansas Valley could be 
reviewed, it would be noted that 600 to 900 pounds per acre were not 
uncommon yields about 25 years ago. The soils of the Arkansas 
Valley were nearly virgin at that time. The soils at that time were 
more or less deficient in nitrates and organic matter. 
In recent years, alfalfa seed yields have greatly fallen off, so 
that 180 to 250 pounds per acre is regarded as a fair seed yield. 
There are two general farm conditions that have undoubtedly. 
