DETAILED STUDY OF SOIL TYPICAL OF EXTENSIVE AREAS. 29 
: 
C 
aN 
= 
. 
< 
: 
S 
= 
S 
8 
Nj 
S 
NG 
RK 
: 
t 
Fig. 18.—Diagram showing the effect of calcium sulphate upon nitrification of ammonium sulphate in 
samples of soil from plat 300, Truckee-Carson Experiment Farm, representing poor soil ‘‘A’’; plat 310, 
representing poor soil ‘‘B”’; and plat 320, representing good soil. 
TasBLeE VII.—Mitrate formed from nitrite by samples of soil from plats 330 and 350, 
Truckee-Carson Irrigation Project, in medium for nitrate bacteria. Incubated at 28° C. 
| Nitrate ; Nitrate 
formed in ormed in | Charaec- 
Nee pepe @ 10 days 20 days ter of 
Dee ; (parts per | (parts per soil. 
million). million). 
Inches 
330 0-6 24. 00 90.32 | Poor. 
6-12 19.68 |- 90. 32 
12-18 12. 60 81. 28 
18-24 19. 80 90. 32 
350 0-6 12. 50 54.19 Good. 
6-12 24. 00 225 
DE Sire | Pee emiercet case rie etait ee Le 
18-24 4.12 90. 32 
211 
