62 
Journal of Agricultural Research 
Vol. VII, No. 2 
more nitrate than is produced by any of the same series when either soil 
nitrogen alone is present or when it is present with sulphate of ammonia. 
The number of such soils is about the same in the Pasadena as in the 
Bay area series, and in no one of them does the nitrogen content go quite 
as low as o.i per cent. They are, besides, soils of large internal surface 
throughout. Of the two other soils, which, in addition to the ones just 
mentioned, produce more nitrate in the blood series than in either of the 
foregoing, both are of large internal surface, and one contains very nearly 
o.i per cent of nitrogen, while the other contains nearly 0.075 per cent 
of nitrogen. 
While on the absolute basis in the dried-blood series the Pasadena and 
Bay area soils are much alike, with the former in some respects superior 
and in other respects inferior to the latter, the difference is more marked 
on the relative basis. Thus, the records made for a percentage trans¬ 
formation of nitrogen into nitrate attain higher values in the Pasadena 
area than in the Bay area soils, and four soils of those above noted trans¬ 
form more than 20 per cent of the nitrogen present into nitrate, while 
three others pass the 15 per cent mark. It will be seen that there is 
only one soil in the Bay area even in the latter class in the dried-blood 
series. The foreign soils behave as a class of humid soils in a diametrically 
opposite manner from the Pasadena area soils with respect to dried blood. 
For the most emphatic proof of this, the reader can compare this para¬ 
graph with that discussing Table I, Group III. 
Cottonseed meal gives in many respects results similar in the Pasadena 
area soils to those obtained with it in the Bay area soils, though in one 
or two respects the two are very different. Thus, for example, 26 per 
cent of the Bay area soils produce less nitrate from soil nitrogen plus 
cottonseed-meal nitrogen than from the former alone. The correspond¬ 
ing figure for the Pasadena area soils is 21 per cent. It is also interesting 
to observe that the last-named value is exactly or very nearly that of 
the analogous figure for the sulphate-of-ammonia series in the two soil 
areas above compared. Most striking of all are the very high absolute 
and almost necessarily high relative amounts of nitrates produced by 
many of the Pasadena area soils in the cottonseed-meal series. Thus, 
while there are among the foreign soils but two which transform more 
than 20 per cent of the total nitrogen in the soil and cottonseed meal 
into nitrate and none such in the Bay area soils, there are nine, or 28 
per cent, of such soils in the Pasadena area group. Moreover, four of 
these nine transform, as indicated, more than 30 per cent of the nitro¬ 
gen into nitrate, and one of these reaches the very high figure of a 57 
pejr cent transformation. That cottonseed meal can be more readily 
and efficiently nitrified in the Pasadena soils as a class than it can in 
the foreign and the Bay area groups of soils is patent. Since, however, 
the Pasadena soils are under the most arid conditions of the three and 
