“Black Alkali" in thl San Luis Valley 
9 
in the same country a high water-plane during the cropping season 
produces good results, why should we attribute the unproductive¬ 
ness of other parts of the same country to a water-plane no higher, 
or to one that is even lower? So far as the variability in the height 
of this water-plane is concerned, there is not much room for move¬ 
ment, in the case stated, from 42 inches below the surface in the 
winter to 12 inches in the cropping season. The permanent water- 
plane in the unproductive section lies within these limits, at about 
*36 or 37 inches, according to my personal observations. 
I do not think that any practical farmer will deny that the 
practical results obtained by the expenditure of considerable sums 
of money on drainage ditches have been disappointingly small. 
These experiments with drainage ditches have been made on a 
sufficient scale and length of time to justify a very good judgment 
of how much is to be hoped for from these alone and, as said, the 
results are disappointingly small. 
ABUNDANT “WHITE ALKALI'' OF VALLEY NOT A 
SERIOUS PROBLEM 
Another fact is that the ordinary “white alkali” which occurs 
abundantly in the valley is not a serious problem, though it has 
been made to appear such. I am not alone in this view of the 
question and know that many practical men are fully convinced 
of this. 
I shall not discuss the question of the occurrence of some 
chlorides in this valley at this time. The nitrate question is really 
of some importance and the occurrence of certain chlorides in this 
fresh water valley is an interesting problem, but they do not con¬ 
stitute the big important fact that I want to present in this bulletin. 
“BLACK ALKALI" PRESENT IN DETRIMENTAL 
QUANTITIES 
This fact is that, while the total amount of alkali in the soil 
of the Hooper-Mosca section is comparatively moderate, the char¬ 
acter of this alkali is very bad. There is present, in most of the 
land, sodic carbonate, “black alkali”, enough to be detrimental, if 
not fatal, to any crop that may be planted. The best information 
at my disposal indicates that the presence of 400 parts of sodic 
carbonate to the million parts of soil is injurious, or possibly fatal, 
while it is probable that few, if any, crops can survive in the pres¬ 
ence of as much as 500 parts to the million. The amount of alkali 
in this land is generally taken at something like 1,000 to 1,200 parts 
to the million. This amount of “white alkali” would not be in the 
least dangerous, but if one-half of it were “black alkali”, very seri¬ 
ous trouble would ensue. In fact, the land would be ruined for all 
practical purposes. 
