72 
The: Colorado Experiment Station. 
nearer to the surface than this. Borings to a depth of six feet and 
more at points more remote, failed to reach the water plane. 
1 hough the water plane at the lower limit of cultivated ground was 
five feet below the surface the soil was wet at a depth of two to four 
inches. The highest portion of this tract is the southeastern corner. 
The slope is from this portion, north and west to the drainage ditch, 
i he central portion of this strip of land was planted to beets in 
1908, 1909 and 1910, but we do not at this time intend to say any¬ 
thing about the beets nor about the land planted to beets, but will 
consider only the cultivated land west of this. I regret that I have 
no photograph of this land, for it is exceedingly difficult for any 
reader who has not actually seen these things to understand even 
the most faithful description or to have any adequate appreciation 
of the facts. In 1910 this land was planted to sorghum. There 
was here and there a little of it that came up but for the most part 
it was a complete failure, the land being entirely bare except along 
the irrigating furrows or lateral where, at the margin, showing the 
limit of the running water, a few small, stunted plants survived. 
1 hese plants were not more than a few, from three to eighteen, 
inches high. I took a sample of this soil on November 2, 1910, 
weighing about forty pounds, and to depths varying from four 
to six inches. This sample was taken for experiments in incuba¬ 
tion, but a preliminary test showed that the soil extract gave very 
unsatisfactory results, in fact, it was a failure. The azotobacter 
seemed to have been killed. The water-soluble portion of this soil 
equalled 4.518 percent of the air-dried soil. A nitric acid determin¬ 
ation made on this sample corresponded to sodic nitrate equal to 
38.867 percent of this water-soluble or 1.756 percent of the air- 
dried soil, being at the rate of 70,240 pounds of sodic nitrate per 
acre-foot; or restricting the calculation to the top six inches actually 
taken, we have 35.120 pounds, or 17.56 tons per acre, a degree of 
concentration which is very difficult for those who know nothing 
about this matter to believe possible. 
The water-soluble in the following sample, 1024, equalled 
5.54 percent. 
