8 
Colorado Experiment Station 
upon the fact that alfalfa has proven beneficial as a crop in farm rotation, 
also from the fact that alfalfa, like other leguminous plants, appropriates 
the larger part of its nitrogen requirements from the air, thus adding this 
element of fertility to the soil. Granting that all this is true, we have the 
questions: How about the other necessary elements of plant food, such as 
phosphorous, potassium, and sulphur? How are these to be supplied? x4nd ■ 
are they not equally necessary in fruit production? For example, three 
tons of alfalfa permanently removes approximately 120 pounds of potash, 
and from 90 to 100 pounds of phosphorous per acre per year, and nothing 
of this amount is returned to the soil. In other words, the taking off of 
alfalfa from the land without returning an equal amount of plant food mate- 
rial in the shape of fertilizer, permanently impoverishes the soil to the extent 
of the amount removed. Permanent hay crops like alfalfa are not adapted to 
orchards, and alfalfa should not be kept for more than three years without 
being plowed under, and in doing this, the second or third crop should not 
be cut for hay. 
The purpose of the cover crops in the orchard is not for the growing 
of feed for livestock, but for turning under so that the soil may be benefited, 
both in the matter of fertility and what is often equally important, in soil 
conditions. 
With few exceptions, the orchards in the whole district show the effect ‘ | 
of poor soil conditions or lack of soil fertility, or both. The lack of proper ij 
pruning is also apparent. The trees in the older orchards are practically | 
stationary in their growth; the foliage is small and lacks the deep green j 
color of healthy trees. The remedies for this general condition are to be j 
found, first, in proper pruning; second, in the plowing up of the old sod : 
in the fall or early spring, in clean cultivation during the early summer, j 
and the seeding of the ground to a cover crop in the fall which is to be|j 
plowed under the following spring. (See Bulletin No. 250, “Orchard 'j 
Management.”) | 
The growing of small fruits and vegetables between bearing fruit trees ^ 
is not profitable. The soil in a bearing orchard is generally too shaded for | 
the crops to do well, and further, the bearing trees need all the fertility that | 
the soil contains. While the trees are small, the land may be cropped, pro- ^ 
vided the fertility of the soil is maintained, and provided cultivation and n 
irrigation do not injure the growth of the growing trees. Cultivated or hoed ii 
crops which mature early should l)e grown, since these permit the proper ;i 
ripening of the trees in the fall before freezing weather sets in. 
A considerable number of orchards are owned by non-residents and 
are cared for by renters. Out of a total of 687 orchards, 172 are owned 
by non-residents, and in addition, a large percentage is owned by residents 
of the county and cared for l)y renters or tenants. As a rule, fruit growing 
by proxy is unprofitable. The renter will naturally take all he can get, 
with the least possible expenditure of money and effort. This is especially 
true when the lease is for short duration. Under the tenant system, the ^ 
