IO 
Colorado Experiment Station 
In order to ascertain how generally the carbonate of soda may 
be distributed throughout this district, I took two sets of samples, 
beginning in the first case a little south of McGinty and con¬ 
tinuing to Hooper, and in the second case a little east of Center 
and continuing to Hooper, but to make the two series continuous, 
I shall give the results from Hooper to Center. 
SODIC CARBONATE IN SOME SAN LUIS VALLEY SOILS IN PARTS PER MILLION 
Black Alkali in 
Parts Per Million 
An old, gone-back ranch. 865.0 
Land in bad condition, crops failed. 375.0 
Land barren for some years. 722.0 
Land barren . 925.0 
Land barren, soil sandy. 5103.0 
Alfalfa field, stand good. 144.0 
Alfalfa field, stand medium, old. 200.0 
Alfalfa field, stand good. 259.0 
Sandy soil, alkali grass, some sweet clover. 121.0 
Diked and flooded soil. 109.0 
Sandy loam, uncultivated. 253.0 
Oats, a failure. 609.0 
Deserted land . 200.0 
Wholly unproductive land, treatment excellent. 510.0 
Wholly unproductive for many years. 3222.0 
Land just surfaced. 200.0 
Land flooded 1916 rye poor. 398.0 
Land flooded 1916* rye, only a little living. 410.0 
Land planted to peas; peas did not live. 633.0 
These samples represent flooded, cultivated and uncultivated 
lands and there is not one of them that does not contain notable 
quantities of this very objectionable salt. We see that flooded 
land planted to rye and containing 398 and 410 parts of “black 
alkali” to the million of the soil produced nothing. Further, that 
no single sample taken was free from this salt, even though some 
of it had just been flooded in the manner that is now frequently 
practiced in this section. The people, at least some of them, 
realize that this method, as practiced, is not a perfect success (see 
the two fields of rye), but they know that it is the best way yet 
adopted to handle this land. 
If we can discover the source and supply of this carbonate, it 
will help us to form some clear notion of our chances of correcting 
the evil. It will help us to form an idea of how much we may hope 
to accomplish. 
“Black Alkali” Comes from Waters of Valley 
The source of this carbonate is the water of the valley. The 
artesian water at Ta Jara, obtained at 65 to 70 feet, is good water, 
and that obtained at Alamosa, at a depth of 923 feet, is also good 
water. This is not the case with the town well or the mill well at 
