Alkalis In Colorado 
55 
ments to the original quantity, but always showed that there had been a 
gain over the quantity with which we started. The gain during the last 
period of five days was almost the same as for the first period of five 
days. The results of the five-day periods indicate that the various 
changes going on in the soil are sometimes greater in one direction and 
sometimes in another direction. This is probably the case in a field. 
Still, where no nitrogen is removed from the soil but such as may escape 
into the air, the results show a net gain of 36 pounds for each million 
pounds of soil in 40 days, and for the nitrates in the soil, a gain of 94.8 
pounds, which corresponds to the changing of 15.8 pounds of nitrogen 
into nitrates for each million pounds of soil. 
BROWN SPOTS ILLUSTRATE EFFECTS OF TOO MUCH NITRATES 
The nitrates, when present in too large quantities, will kill our cul¬ 
tivated plants, and we find that too much will also kill out these little 
plants that get their nitrogen from the air. The reason that these 
brown spots, of which the ranchmen complain that nothing will grow 
on them, are actually bare, is because of the presence of too much of 
these salts. I am sorry that I do not know how much or rather how 
little of these nitratres it takes to kill vegetation and that I do not know 
how they kill it, but it is certain that they kill. I put some sodic nitrate, 
from 5 to 25 pounds around each of a number of apple trees. I injured 
every one and killed one in four days. This was satisfactory proof 
that nitrate in too large doses, even 5 pounds to a tree, is poisonous to 
apple trees. 
IRRIGATION IS CARRYING ALKALI FROM HIGH LANDS TO LOWER 
LEVELS 
There is a very general notion that water brings the alkalis to the 
surface of the ground. There is no doubt but this is so in a certain 
measure, but it is also very often true in Colorado that it brings them 
“in’", that is, that they are moved from the high lands to the low lands. 
This, however, can not well be the case with the two sections of coun¬ 
try that we have told about in this bulletin, for the only high lands 
from' which the alkalis could be washed are the mountains, and I have 
already told in what sense the alkalis are really washed from the moun¬ 
tains into the soil of the valley. But this is not what we mean when 
we speak of the alkalis being washed from high land down on the low 
land. In this case we mean that there is land, perhaps hills, into which 
former waters have carried alkalis and left them, or perhaps the alkalis 
now forming have accumulated there because there has not been water 
enough to wash them out before this, but now that we have been water¬ 
ing these lands, this water is carrying the alkalis to lower lands as it 
flows down to them. This is really happening in a great many places 
