306 Proceedings Indiana Academy of Science 
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FIGURE I. 
Correlation of Bacterial Activities and Nitrate Production. 
CORRELATION OF BACTERIAL ACTIVITIES AND NITRATE PRODUCTION 
(Figure I). 
This graph is based on the figures in Table 8. It can be readily 
seen that there is a marked correlation between these five basic factors. 
One noticeable disagreement may be seen in the case of the treated 
incubation test on Plot No. 9, when the nitrates were comparatively 
higher than in the other tests. Another disagreement occurs due to 
high bacterial counts for plots Nos. 10 and 11. With the exception of a 
few other minor differences these curves follow each other very closely. 
COMPARISON OF CROP PRODUCTION WITH AN EFFICIENCY FACTOR 
(Figure II). 
Any effort to compare the nitrate production and bacteriological 
efficiency of a soil with crop production makes it desirable that some 
common basis of comparison should be decided upon. For this purpose 
an efficiency factor for each of the tested plots was secured by adding 
together the parts per million of nitrates from the three tests with the 
mold and bacteria counts per million for each plot using the last five 
columns of figures in Table No. 8. The sums obtained for check plots 
Nos. 1 and 5 were added, divided by two, and the resulting figure taken 
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