16 
Bulletin 99. 
Some other facts at which we have arrived are of interest 
in this connection, i. e., the actual manurial value of the stubble. 
On an acre of alfalfa taken to the depth of six inches it is worth, 
estimated in the same manner that we have estimated the manurial 
value of the hay, not far from $20.00 per acre, while the roots 
below the depth of six inches possess a value of $16.00, or the 
stubble and roots together have a value of about $36.00 per acre. 
It may be a rather difficult task to turn under a growing crop of 
alfalfa in middle or late spring, but it is also difficult to correctly 
estimate the great manurial value of the excellent material thus 
added to the soil; it is certainly very much in excess of the figures 
given above . 
There is still another respect in which alfalfa is probably our 
best crop to use as a means of benefiting the soil. It has been 
intimated, though not explicitly stated, that our soils are often 
very firm at shallow depths, so much so that it is very probable 
that scarcely any cultivated plant may be able to reach the greatest 
depth to which it can and would feed under ordinarily favorable con¬ 
ditions. A good stand of alfalfa, say three years old, will probably 
have 500,000 plants to the acre, or more than ten plants to the 
square foot, every one of which penetrates the soil to a depth much 
greater than the usual feeding depth of such plants as potatoes, 
beets, wheat, etc. They not only in this way open up the soil to 
the attack of less vigorous roots, but fill these channels with a 
supply of plant food, accompanied by a mass of organic matter 
that by its decay may bring still more plant food into available form. 
This subject of preserving and even of increasing the fertility 
of our soils cannot be too strongly urged upon the attention of 
our agricultural population. 
While our soils contain a large amount of potash in the total, 
due to the presence of the potash felspar, the amount of 
the available potash is not extraordinarily large, and that 
locked up in the felspar is only slowly becoming available, 
too slowly to replace that removed by crops. Our soils are poor 
in organic matter and only fairly well provided with nitrogen. 
Our climate does not favor the formation of humus, nor do our 
soil conditions as a rule. The best means at our disposal to meet 
these conditions and to maintain our good yields are, I believe, 
to husband all the material available for conversion into well-rotted 
barnyard manure, our alfalfa, all of which should be fed, if possible, 
on the farm which grows it, being of great value for this purpose. 
All of the straw, while of itself not of very great value, can be 
used to good advantage and should be so used. 
Our alfalfa is an excellent plant to turn .under as a green 
manure, but owing to facts which are evident to every ranchman, 
this involves a certain rotation of crops, at the end of which a good, 
vigorous growth of alfalfa can profitably be added to the soil. 
