IO 
THE COLORADO EXPERIMENT STATION 
PAGE 
form occurs near the surface; the second is most abundant 
at depths of from three to five feet; and the third at all depths 
up to eleven and a half feet. Illustrated in Plates XI. and 
XIV.; also shown in Plate XIII. Partial analysis of nodules 
page 53. 
Ratio of Roots to the Tops . 53-54 
This ratio varies greatly with individual plants. In field 
culture it is more than an average alfalfa plant on which the 
top equals or exceeds the weight of the root. 
Alfalfa Stubble . 55 
The stubble, taken to a depth of six inches, five days after 
cutting, is equal to about two thirds of the weight of the green 
alfalfa as cut by the mower. The dried stubble found per 
acre ranging from 2.5 to 3.34 tons. 
Composition of the Stubble . 56 
Analysis of ash of stubble, page 92. 
Mineral constituents per 1,000 pounds of stubble, page 56. 
Composition op the Roots . 56-58 
Analyses of ash of roots, bark, and inner portion, page 92. 
Methods of preparing roots—could not wash them, page 56. 
Fresh roots contain 60.41 per cent, water. Fodder analyses 
of root, page 57. Ash constituents are easily washed out of 
the roots. Properties of aqueous extract of roots, page 57. 
The presence of starch doubtful. Mineral plant food con¬ 
tained in each 1,000 pounds of air dried roots, page 58. Ash 
constituents dissolved out of roots by water equal 11.99 pounds 
per thousand. Phosphoric and sulphuric acids, but particu¬ 
larly potash, went into solution. 
Manurial Value of Stubble . 59 
Each ton of stubble contains 8.31 pounds of phosphoric acid, 
15.52 pounds of potash. 36.37 pounds of nitrogen; giving the 
value of the stubble at $6.75per ton, or $19.28 per acre. 
Manurial Value of the Roots . 60 
The weight of roots per acre is nearly twice as great as that 
of the stubble, but is not so rich in phosphoric acid and 
nitrogen; the manurial value of the roots per acre is about 
$16. 58. Without assigning any value to the organic matter 
we have $35.90 as the value of the alfalfa stubble and roots. 
This food is within the reach of ordinary plants; wheat for 
example. If the alfalfa roots were removed, the soil would 
be found poorer than before the alfalfa was grown on it, es¬ 
pecially in nitrogen, the first nine inches of soil excepted, 
page 61. 
