the seed, and produce
partial inoculation. Other causes are more obscure. The cowpea trails
on the ground, and carries its bacteria more successfully than the
soybean. Most legumes require a soil artificially inoculated when
brought into a new region, failing otherwise in some degree to make
full growth.

Method of Inoculation.--The bacteria can be transferred to a new field
by spreading soil taken from a field that has been growing the legume
successfully. The surface soil is removed to a depth of three inches,
and the next layer of soil is taken, as it contains the highest
percentage of bacteria. They develop in the nodules found on the
feeding roots of the plants. The soil is pulverized and applied at the
rate of 200 pounds per acre broadcast. If the inoculated soil is near
at hand and inexpensive, 500 pounds should be used in order that the
chance of quick inoculation may be increased. The soil should be spread
when the sun's rays are not hot, and covered at once with a harrow, as
drying injures vitality. The soil may be broadcasted by hand or applied
with a fertilizer distributer. The work may be done at any time while
preparing the seed-bed. The bacteria will quickly begin to develop on
the roots of the young plants, and nodules may be seen in some
instances before the plants are four weeks old.

Pure cultures may be used for inoculation. Some commercial concerns
made failures and brought the use of pure cultures into disrepute a few
years ago, but methods now are more nearly perfect, and it is possible
to buy the cultures of all the legumes and to use them with success.

Prices continue too high to make the pure cultures attractive to those
who can obtain inoculated soil with ease. If land has been producing
vigorous plants, and if it contains no weeds or disease new to the land
to be seeded, its soil offers the most desirable means of transferring
the bacteria.

The claim is made by some producers of pure cultures that their
bacteria are selected for virility, and should be used to displace
those found in the farmer's fields. The chances are that, if soil
conditions are good, the bacteria present in the soil are virile, and
if the conditions are bad, the pure cultures will not thrive. All
eastern land is supplied with red clover bacteria, just as some western
land possesses alfalfa bacteria, and partial clover failure has causes
wholly apart from the character of its bacteria.

We do not have definite kno