102 J. K. TAYLOR. 
Table VI.-—MNitrate Nitrogen in pounds per acre to a depth of 
18 inches. i 
Soil. | July | Aug. | Sep.* | Oct.* | Nov.*| Dee. | Jan. | Feb. | Mar.) 









| Lucerne| 17 | 27 | 18 197) 22 | 18/560 Reena 
| PA | 31) 15] 21-4} 19} 15 | 181) Soni Rie eames 
| PB | 42) 12) 25 | 10) 10°) 11 | 2 ease 
| PC 31 |. 19: | 30% 18 | 38 | 250). 2ce eae 



* Since no subsoil samples were taken in September, October, and 
November the total has been got by doubling surface soil figures which 
would probably be to the advantage of those months. 

The graph (Fig. 2) accompanying the table brings out its 
features more clearly, but it is unfortunate that the figures. 
for September, October and November are approximate 
only. We seem however to have peaks in the curves at 
July-August and January. The cultivated fallow (PC) 
offers a puzzling variation by the fall in December. PA 
and PB are in close parallel and PO and “‘Lucerne’’ more 
or less agree as to curves. If we assume “ Lucerne”’ to be 
slightly earlier than the others, then PA, PB and it are in 
no great opposition. Finally the magnitude of the curves 
is a disappointing revelation by the side of the results. 
obtained in other countries. 
Nitrifying Power of Soils. 
It is generally assumed that the nitrifying power ofa 
soil is a fairly constant figure; indeed the whole theory of 
judging fertility by nitrifying ability depends on this assump- 
tion. Now estimations of nitrification for the same plot 
at different times of the year leave room for difference in 
three places—first by sampling error, second by experi- 
mental error, third by real difference. Regarding sampling 
it can only be said that in all cases the soil was collected 
personally in exactly the same way with a soil auger. 
Then to test out experimental methods a small series was 
run using exactly similar methods and conditions. The 


