Fixation ot Nitrogkn in Cotorado Soils 17 
tAveen the last sample ^veii and this is not more than 1200 
feet. A portion of the field from which this sample was taken 
was planted to pop corn in 1910. Some of it ^rew well and 
some of it did not. It had no water. 
AN AI.YSIS OF WATKH-SOI.IJBI.K, SOIL Laboratory No. 2«07 
AVatcr-‘-oliible equaled 9.704 percent air-dried soil. 
Percent 
(''alcic sulfate 28.245 
Ma.g'nesic sulfate 0.853 
Mag-nesic nitrate 44.930 
Fo-’ic nitrate 4.525 
Potassic chlorid 3.186 
Sodic chlorid 17.799 
Excess sodic oxid 0.462 
100.000 
The samples were washed till all sulfate disappeared from 
the wash -water. This means that we washed out any gypsum 
that may have been present in the soil. 
The next sample was virgin soil which was very wet at the 
time the sample was taken. The location was so unfavorable 
that I hesitated about taking any sample, but it was either this 
place or none. The analysis was a troublesome one owing to 
the presence of much organic matter. The excess of bases, ex- 
pressed as sodic oxid, is high, still I think that the determin- 
ations are correct and that the analysis shows very nearly the 
actual mixture of salts present in the soil. 
ANALYSIS WATER-SOLUBLE, SOIL Laboratory No. 2609 
Water soluble equaled 8.71 percent air-dried soil. 
Percent 
Calcic sulfate 22.454 
Magnesic sulfate 13.225 
^ Magnesic chlorid 18.219 
Magnesic nitrate 18.617 
Sodic nitrate 19.520 
Potassic nitrate 4.056 
Excess sodic nitrate 3.909 
100.000 
The next sample was taken about 6 miles further soutli 
where the conditions were much better, but still not good. The 
reason for this long jump in this series of samples has been 
stated in a previous paragraph. The drainage at this point was 
fairly good and the land under ordinary conditions should be 
good, productive land, at least much better than it is. Tlie sam- 
ple of soil was taken to represent the field. Had we wished 
to gather a sample rich in nitrates this could have been done 
as it was evident that there were spots where these salts were 
abundant. The sample represents a strongly alkalized soil 
