356 
Journal of Agricultural Research 
Vol. VIII, No. 9 
as was found for the cropped plots. The total salts do not show the 
tendency to decrease with increasing water, although the 40-inch appli¬ 
cations caused a rather marked decrease over other moisture treatments. 
The nitrate decline with increasing water was such that the ratio of 
the total salts to sodium nitrate increased from about 8.9 to 1 with no 
water applied to 16.2 to 1 where the application was 40 inches. The in¬ 
crease in the ratio of total salts to nitrates from 10.2 to 1 to 11.7 to 1 
between the first and the fourth feet shows the nitrates to decrease more 
rapidly with increasing depth than do the total salts. It will be noticed 
that the ratio of total salts to nitric nitrogen is about 10 times what 
King found it to be for humid soils. 
RELATION OF CROPS TO SALTS AND MOISTURE 
Figure 18 gives the combined yields of grain and stover per acre for 
three years of this experiment. 
Table VII .—Summary of nitrates\ total soluble salts , percentage of soilmoisture , and yield 
of crops with different applications of manure . Average of all moisture treatments for 
three years 
Quantity of manure. 
Moisture. 
Sodium nitrate. 
Total soluble salts. 
Crop 
yields. 
Cropped. 
Fallow. 
Cropped. 
Fallow. 
Cropped. 
Fallow. 
None.. 
5 tons. 
15 tons. 
Average. 
Per cent. 
14.9 
13 - 4 
14 - S 
Per cent. 
IS -5 
IS-2 
16. 2 
P. p. m. 
11. 2 
8.6 
12.8 
P. p. m. 
23-4 
32-9 
41.9 
P. p. m. 
345 
296 
302 
P. p. m. 
377 
384 
347 
Tons. 
4. xo6 
6.273 
7 - 053 
14-3 
15-6 
io. 9 
32 - 7 
314 
369 
5- 811 
Table VIII .—Summary of nitrates, total soluble salts , percentage of soilmoisture, and yield 
of crops with different irrigation treatments. Average of all manuringsfor three years 
Water applied. 
Moisture. 
Sodium nitrate. 
Total soluble salts. 
Crop 
yields. 
Cropped. 
Fallow. 
Cropped. 
Fallow. 
Cropped. 
Fallow. 
None. 
5 indies. 
10 inches. 
20 inches. 
30 inches. 
40 indies. 
Average. 
Per cent. 
10.3 
11.9 
14.4 
15-4 
16. 7 
16.9 
Per cent. 
13 - 4 
14 - 5 
15 - 4 
16. 2 
17.0 
17-3 
P. p. m. 
14. 7 
12 .2 
12.3 
9.2 
9.4 
7-2 
P. p. m. 
42-5 
42.3 
34*7 
30.8 
26.9 
19. a 
P. m. p. 
360 
325 
307 
304 
320 
270 
P. p. m. 
378 
37 i 
363 
385 
407 
311 
Tons. 
5-155 
5-993 
6.026 
6. 246 
5.891 
5 - 58* 
14-3 
15-6 
10.8 
32.7 
314 
369 
5.811 
In Tables VII and VIII are found the summarized results of the effect of 
manure and water, respectively, on the moisture, total salts, and nitrates 
found in the soils from which the crops were taken, compared with 
adjacent land on which no crops had been grown. The increase in crop 
is much greater in proportion for 5 tons than for 15. Except for the 
5-inch application of water with 15 tons of manure, the largest yields 
were secured with 20 inches of water. The effect of cropping is felt 
