308 
Journal of Agricultural Research 
Vol. IX, No. 9 
has been brought up from below 6 feet. It is also interesting to note 
that, while the total nitrogen disappearing from each plot bears a rela¬ 
tionship to the water applied, the quantity per inch of water is greatest 
where only 15 inches of water were applied. In fact, it is twice as great 
as where 37.5 inches of water are applied to the soil (Table VI). 
Table VI.— Summary of nitrogen transformations in alfalfa soil 
[Results expressed in pounds] 
Water applied. 
Character of nitrogen. 
inches. 
25 inches. 
15 inches. 
None. 
Nitrogen removed in crop.. 
Nitrogen in soil in spring. 
Nitrogen in soil in fall. 
Original soil nitrogen removed. 
Nitrogen formed during season. 
Excess of nitrogen formed during season in the 
irrigated plots. 
282. 5 
5 
23*4 
—12. 9 
2 95 * 4 
128.3 
3*4 
265 
11 
35*9 
—24.9 
289.9 
122. 8 
4.9 
259.1 
22. 7 
32.5 
“ 9*8 
268. 9 
101. 8 
6.8 
170. I 
44 * 9 
41.9 
3*0 
167.1 
Excess per acre-inch of water. 
2 .—POTATO LAND 
The plots in the series on potato land were four in number. One 
received 37.5 inches, one 25 inches, one 15 inches of irrigation water, 
while one was unirrigated. All other conditions of the plots were kept 
as nearly uniform as possible, so that any difference which is found to 
exist in the nitric nitrogen must be due to the variable factor—the water 
applied. The average results for the three years are given in Table VII. 
Table VII.— Nitric nitrogen in potato land—Average for three years 
[Results expressed as pounds per acre] 
Plot No. 
Period. 
Water ap¬ 
plied in 
five applica¬ 
tions. 
Depth of soil. 
1st foot. 
ad foot. 
3d foot. 
4th foot. 
Sthfoot. 
6th foot. 
Total. 
Inches. 
35 . 
Spring. 
37*5 
II. 4 
12. 2 
2 * 3 
2.7 
2. 2 
2,9 
33*7 
36 .. 
25.0 
!7* I 
8. 2 
8.9 
7*9 
5 *o 
2. 8 
49*9 
.. .do... 
15. 0 
20. ? 
8 . 7 
4. 0 
4 . O 
2.1 
A 0 
A A, 1 
8 ” . 
None. 
10. 9 
f 
29. O 
43-6 
T' w 
46.4 
0* * 
38*5 
T v 
27.9 
‘rt* O 
196.3 
35 . 
Summer... 
37*5 
2. 6 
2. O 
12. 8 
7*9 
8.4 
4*3 
38.0 
36 . 
25.0 
9.8 
4.4 
8.9 
6*3 
6.7 
8*3 
44.4 
37 . 
x 5 - 0 
16.1 
* 5 * 2 
7.2 
3 * 2 
3 *o 
2.4 
47.1 
38 . 
None. 
2 5 * 9 
8.9 
17*5 
2 5 * 1 
18. 4 
r 7 * 9 
ii 3*7 
35 . 
Fall. 
37*5 
9.9 
6.1 
3*7 
4*9 
3 *o 
3*9 
3 i *5 
36 . 
25.0 
18. 9 
5*5 
6. 2 
7*9 
5 * 2 
4.2 
47*9 
37 . 
15.0 
10. 9 
3*7 
2 * 5 
6. 6 
7.2 
4.4 
35*3 
38. 
,..do. 
None. 
34 * 6 
17. 6 
9.8 
ii *5 
19. 1 
9.6 
102. 2 
