178 REPORT OF THE DEPARTMENT OF BOTANY OF THE — 
some of the failures with alfalfa in New York are to be attributed 
to hardpan. Stone,'’ after reviewing the experiences of the spring 
of 1904 when alfalfa in New York was found badly winterkilled 
says: “ This indicates that while alfalfa may succeed on lands with 
somewhat impervious Subsoils, yet on such subsoils the crop is much 
more liable to damage than upon those of a more porous nature.” 
There has come to our attention one quite remarkable case of 
success with alfalfa over hardpan. A farmer at East Bloomfield, 
N. Y., entered into an agreement with the Bacteriological Depart- 
ment of the Station to conduct a cooperative experiment on soil. 
inoculation for alfalfa. The plat of land used contained one acre 
and was so situated on the brow of a hill that the surface drainage 
was excellent, but it was not underdrained. The soil was clay loam, 
underlaid with hardpan at a depth of only five inches! The seed 
was sown June 12, 1905. The young plants prospered and passed 
the first winter safely. During 1906 three cuttings were made and 
a total yield of about six tons of cured hay obtained. The field 
was not seen by a Station representative during 1907, but the owner 
reports that 1t was again mown three times, the yield being about 
four tons of cured hay. 
SOIL DEFICIENT IN HUMUS, 
Many New York soils are greatly deficient in humus. This is a 
condition which militates against success in starting alfalfa. It 
may be remedied by plowing in clover or by the application of stable 
manure. Stable manure is exceedingly useful. As a rule, it should 
be plowed in the fall before seeding. If used as a top dressing im- 
mediately before sowing it must be thoroughly rotted to avoid the 
introduction of weeds which will surely make serious trouble. 
SOIL DEFICIENT IN NODULE-FORMING BACTERIA, 
It is a well known fact that alfalfa will not thrive unless the 
roots bear the so-called nodules.” 
These are caused by bacteria, Pscudomonas radicicola ( Beyer.) 
Moore.* Some soils will not produce alfalfa because they are 

* Stone .0G, Da7). 
"The literature of this subject prior to 1903 has been collected by Mac- 
Dougal (61) and Schneider (090), (91). See also Atkinson (2) and 
Jacobitz (49). 
"* Recent investigations by de’Rossi (83a) indicate that the so-called 
bacteroids, and not Pseudomonas radicicola, are the cause of the nodules. 
Heretofore, the bacteroids have been regarded as an involution form of Ps. 
radicicola, but de’Rossi holds that they belong to a distinct species, 

