jan. 31,1916 Bacterial Activity in Soils and Crop Production 
859 
Table IV .—Nitrification of ammonium sulphate on rotation plots in iqii 
Plot No. 
Quantity of nitrogen. 
Test 1. 
Test 2. 
Test 3. 
Test 4. 
Mgm. 
Mgm. 
Mgm . 
Mgm. 
5 * 019 
I 7 - 577 
7 - 565 
8. 086 
8. 075 
21. 625 
9. 788 
11.789 
604.. 
12. 630 
24- 517 
12. 903 
19. 419 
7. 066 
21.477 
n -357 
I 3 - 749 
11. 908 
22. 978 
9. IOI 
10. 620 
6. 724 
21.477 
8. 310 
9 - 655 
Table V .—Azofication tests on rotation plots in iqii 
Plot No. 
Quantity of nitrogen. 
Test 1. 
Test 2. 
Test 3. 
Test 4. 
601. 
Mgm. 
9 * 50 
17.46 
20. 64 
14. 27 
18. 25 
14.27 
Mgm. 
3 * 93 
i 5 * 07 
18. 25 
17.46 
15 - 87 
11.88 
Mgm. 
z 3 - 52 
ig. 92 
23. 12 
20. 72 
18.32 
16.72 
Mgm. 
10. 32 
z 7 - 52 
20. 72 
18.32 
l6. 72 
15. 12 
602. 
604. 
607. 
600. 
001.. , 
The variations in the amount of moisture in the different plots at the 
same samplings were very small and the differences in bacterial activities 
which were found could not, therefore, be attributed to the different 
moisture conditions in the plots. 
The yields obtained with corn on the various soils are given in Table 
VI, and comparing these with the ammonification, nitrification, and 
azofication results it will be noted that there is a remarkably good 
agreement. 
Table VI .—Yield of corn on rotation plots in iqii 
’ Plot 
No. 
Treatment. 
Yield per 
acre. 
601 
Continuous com. 
Bu. 
35 - S 
46. 0 
So- 7 
S 2 - 7 
602 
2-year rotation.. 
604 
607 
3-year rotation. 
2-year rotation; clover turned under.. 
609 
2-year rotation; cowpeas turned under. 
3 2 - 5 
901 
2-year rotation; rye turned under. 
43 - 2 
The ammonification results with the dried blood and cottonseed meal 
did not always run exactly parallel, but the differences were slight, and 
in most cases the same comparisons were secured, so they need not be 
