3 1 6 Journal of A gricultural Research vd. ix, no. 9 
If we assume that all of the nitrogen which is removed by the oats or 
com is nitrified before removal and then compare these results with those 
obtained on the fallow soil, we find that the fallow soil is short 77 pounds 
of nitric nitrogen. This quantity minus the extra quantity formed, due 
to the stimulating action of the plant upon the nitrifying organisms, may 
be taken as the minimum quantity which is leached out of this plot 
during the season or converted into other forms by bacteria. The 
loss from leaching in the case of the cropped plots would be much lower, 
but even here the loss from leaching where excessive quantities of water 
are used is considerable. 
PLOTS RECEIVING 2$ INCHES OF IRRIGATION WATER 
There were five plots in this series, so arranged that the cropped plots 
can be compared with each other, and these in turn with the fallow. 
Since the treatment which the plots in this series have received, such as 
plowing, cultivation, etc., has been as nearly uniform as possible, the 
variable is the crop. The marked difference, therefore, in the several 
plots must be due to the influence of the crop upon the movement and 
production of nitric nitrogen. The average results for the three years 
are given in Table XVI. 
Table XVI .—Nitric nitrogen in soil with various crops and receiving 2 5 inches of 
irrigation water—Average for three years 
[Results expressed in pounds per acre] 
Period. 
Crop. 
Depth of soil. 
Total. 
istfoot. 
2d foot. 
3d foot. 
4th foot. 
5th foot. 
6th foot. 
Spring. 
Do. 
Do. 
Do..... 
Do. 
Summer. 
Do. 
Do. 
Do. 
Do. 
Fall. 
Do. 
Do. 
Do. 
Do. 
Alfalfa. 
Oats. 
Com. 
Potatoes. 
Fallow. 
Alfalfa. 
Oats. 
Com. 
Potatoes. 
Fallow. 
Alfalfa. 
Oats. 
Com. 
Potatoes. 
Fallow. 
1.9 
15.8 
7.2 
*7* 1 
10 0 
2.4 
2. 6 
*• 7 
9.8 
3-5 
14.9 
4. 0 
3-7 
18. 9 
16.5 
2. 0 
4 9 
23 
8.2 
6.0 
3-2 
i -7 
1. 6 
4*4 
13*4 
9*0 
3*2 
3 -o 
5*5 
7*9 
1.8 
3*4 
2. 0 
8.9 
4*8 
2*3 
3*2 
5*5 
8. 9 
13*1 
3*2 
3 *o 
2. 2 
6.2 
9 - 7 
1*4 
5-3 
i *9 
7*9 
5*5 
1.8 
2.8 
3*9 
6*3 
15*2 
2.4 
2.7 
2.7 
7*9 
6. 0 
u 
1.9 
5*0 
10. s 
1.4 
2.4 
1.9 
6.7 
19. 6 
2. 0 
2.8 
2.4 
5*2 
7*8 
I * 4 
43 
2. 2 
2.8 
I9.4 
*•5 
3*3 
2. 2 
8*3 
7*9 
4*4 
2. 6 
3*2 
4.2 
4 * 5 
11. 0 
35*5 
* 7*5 
49*9 
56.3 
12. 6 
16. 0 
16.8 
44 * 4 
72.7 
35*9 
18.3 
17. 2 
47*9 
52.4 
It may be seen that during the spring the nitric nitrogen of the alfalfa 
soil is very low, and the quantity present is about equally distributed 
throughout the 6 feet, while in the other plots the total quantity is much 
higher. Especially is this true in the potato and fallow soil, and we 
