32 Report OF DEPARTMENT OF BACTERIOLOGY OF THE 
INTRODUCTION. 
This publication summarizes the results of co-operative ex- 
periments which have been conducted in practically all parts 
of this State since 1905. The object of these experiments was 
to get a measure of the real need of inoculation and of lime in 
connection with the growing of alfalfa on the farms of this 
State, and, so far as possible, to determine the relative import- 
ance of these lines of treatment in connection with the growing 
of this crop. 
Any study of this kind should be made upon a comparatively 
large amount of data in order to arrive at dependable results; 
and in securing this data quality should not be sacrificed for 
quantity. Moreover, if the results are to represent general 
relations it is necessary that the cases studied shall be so 
selected as to represent average conditions. 
In this study, experiments have been conducted on about 200 
farms scattered through the agricultural portions of this State. 
However, the necessity of basing the conclusions upon depend- 
able experiments only has made it necessary to eliminate nearly 
one-half of these because of serious mistakes in laying out or 
conducting the experiments or of failures to report the required 
data. While this exclusion was solely for the reasons named 
it has acted in a somewhat. selective manner since in those 
cases where the experiment early became a failure from natural 
causes there was a greater tendency to neglect to furnish the 
required data than in the cases where it seemed a success from 
the farmer’s point of view. 
As a result of this, the percentages of success in growing 
alfalfa are probably higher, in the results here given, than they 
would really be in practice. However, this error can not be 
very large, since the untreated check plats here recorded only 
show a successful crop in 20 per ct. of the cases. It is hard 
to believe that in the days before the need of inoculation and 
of lime was understood the failure in growing alfalfa in this 
State occurred oftener than four cases out of five. 
