44 
Bulletin 65. 
soil is very varying, and that the samples were not taken from the 
same places in the plot. This variability in the soil is shown with 
greatest certainty in the amounts of potash in the different samples, 
these amounts varying much more than can justly be attributed to 
analytical errors. The series of samples in which I have made such 
determinations may serve as a measure of the changes which the 
cultivation of this soil had effected in the time elapsing between the 
taking of the samples The nitrogen determinations for the year 
1897 have not been taken from the table of “Analyses of Soils, Gen¬ 
eral Samples,” but were made on special samples. The samples for 
1899 are sufficiently described as manured and not manured, the 
manure having been applied in 1898, one year before the samples 
were taken. 
TABLE XIX.—TOTAL NITROGEN IN THE SOIL. 
1897. Per cent. 
Sample A.0.0920 
Sample B.0.0945 
Sample C.0.0829 
Sample D.0.0819 
Sample E.0.1382 
Sample F*.0.1081 
1899. Per cent. 
No. 3, not manured.0.0935 
No. 3, manured.1.1700 
No. 2, not manured.0.1355 
No. 2, manured.0.1295 
No. 1, not manured. 0.1316 
No. 1, manured.0.1312 
§ 90. The samples have been arranged in this table so that 
those representing the same general sections stand as nearly oppo¬ 
site each other as possible, but they are not identical. 
§ 91. The samples were taken in the same month of the year, 
and, so far as seasonal influences upon the nitrogen content are con¬ 
cerned, are comparable. The water received in 1899 was greater 
than in 1897. The general effect indicated is an increase of nitro¬ 
gen for the whole plot. 
§ 92. No effort was made to follow the formation of nitrates 
in the soil from day to day, or from week to week, but the amount 
of this substance eliminated in the ground water was determined 
weeklv for the seasons of 1897-98-99 and 1900. The nitrates have 
been determined in but a single series of soil samples, representing 
'the first and second two inches of the soils which had received no 
^manure. The water-soluble, analyses of which have already been 
given, was determined in the same set of samples. The results are 
given in parts per million of the air dried soil. 
* Sample F is the subsoil. 
