The Fixation oe Nitrogen. y 
deliquescent salts. The sample of surface soil taken on this date 
contained 5.91 percent soluble in water. 
ANALYSIS* I 
Water-Soluble 
laboratory 
No. 873 
Nov. 23, 1909 
Percent 
Calcic sulfate . 20.360 
Magnesic sulfate . 6.655 
Magnesic chlorid . 0.459 
Potassic chlorid . 1.292 
Sodic chlorid.*. 45.229 
Sodic nitrate. 25.843 
Iron and Aluminic oxid. Trace 
Manganic oxid . 0.032 
Silicic acid . 0.130 
100.000 
This analysis shows the presence of five tons of nitrates, cal¬ 
culated as sodic nitrate in the top two inches of soil or a trifle over 
thirty tons calculated on an acre-foot. 
I again visited this orchard for the purpose of further investi¬ 
gating the question of the water table on December 3. It has 
been stated that on June 12. we dug a hole five and a half feet 
deep near a tree which had recently died. On this date, December 
3, we dug another hole at the same place six and a half feet deep. 
The ground was quite wet at this depth but there was no free 
water. It has already been stated that the soil is a sandy loam, and 
it was sandier at this depth. Another hole was dug seven and a 
*In this bulletin all of the analyses have been calculated to one 
hundred. This has been done because we believe that the reader will 
be able to compare the results more easily, as they are all reduced to a 
common basis, i. e., parts per hundred of the dry residue—also to save 
space. Many of the samples presented difficulties, mostly owing to the 
presence of very deliquescent and easily decomposed salts such as the 
chlorids and nitrates of calcium and magnesium—and in a few cases of 
large quantities of organic matter. 
The nitric acid determination in a few samples is undoubtedly too 
low because of the presence of magnesic nitrate and the continued dry¬ 
ing necessary to obtain a manageable residue. Some of these samples 
intumesced badly and emitted an acid odor, during which some loss of 
nitric and hydrochloric acids probably took place. The nitric acid was 
determined in duplicate in every case as NO, and the NO absorbed by 
means of a recently boiled FeCL solution. I believe that the results as 
presented in the analyses represent the composition of the water-soluble 
portion of the soils in a water-free condition with a very fair degree of 
accuracy. It is not, however, intended to assert that the nitric acid is all 
combined with one base, as appears in the greater number of the analyses, 
as for instance as sodic nitrate. This is simply a convenient manner of 
combining it and may in some cases be correct, but in many of these 
residues it is probably not correct. 
There is almost uniformly a trace of manganese in these aqueous 
extracts, but it has been disregarded for the most part as it seldom 
exceeds two or three hundredths of one percent. 
