Fixation ot Nitrogivn in Colorado Soils 9 
that even great big inaccuracies cannot conceal nor in any 
serious degree affect them. 
The first sample of soil presented represents a piece of 
ground that had been planted to beets the preceding year, but 
the crop was for the most part a failure. The surface of the 
ground was black and shining. This field was separated from 
a tract of virgin prairie-land by the public road. We did not 
attempt to ascertain the height of the water plane, because 
there was a well at the end of the tract, probably 300 feet to 
the east of the point where the sample was taken and only a 
very little, if any, higher. This well is 25 feet deep and had 
at the time apparently about 5 feet of water in it. While this 
may indicate the water level for this land in a general way, it 
cannot be taken as indicating that the water plane in the land 
where we took the soil sample may not have been materially 
higher. My judgment is that it was because I have found at 
other points that there may be small basin shaped areas of 
varying size with impervious bottoms which may be almost 
filled with water, but if one passes through this bottom in dig- 
ging a hole, little or no water will come in below it. 
I make mention of this fact because the water plane in tlie 
well may be, for the reason here stated, misleading in regard 
to the height of the water plane where the sample was taken 
and I did not make this an object of study at this point. This 
sample was collected about 4 years ago and this land has con- 
tinued to grow worse during the intervening period. I do not 
know the history of this land nor how long it had been under 
irrigation at the time the sample was taken. There is very 
little land under the irrigating ditch to the east or north of 
this, so that the amount of seepage that may flow into or 
through this land cannot under any circumstances be very 
great. It is true that there may be leakage from the irrigating 
ditch, which carries water at times. I do not know how long it 
carries water each season nor the amount of leakage. The ditch 
is located a little to the east of this, point and I believe that 
there is no irrigated land beyond this ditch to the east. The 
east flank of the valley rises rather abruptly only a little way, 
from 1/2 to 2 miles, to the east of this and beyond it lies a dry- 
land country. ■ - ' - 
