Pullman herald. [volume] (Pullman, W.T. [Wash.]) 1888-1989, 1912-09-20
Alfalfa Yields Diminishing

uected Especially was this true of
,S.t norton of the territory where
,rr,eation is not used. The newly
..adod fields (where alfalfa had not
eon previously grown as well as
40 fields where the crop had been
~.own for the past three or four
Years, did not return the yield they
should.
The writer recently had occasion to
.,,,. a number of fields in Latah and
NJ, perce counties, Idaho, and Whit
nan county, Washington. The plants
lowing in fields which were sown in
.ho spring of 1911 Except those hav-
inc grown alfalfa before) were small,
vollow and unthrifty. Dotted here
and there were single plants or small
groups of plants more thrifty than
the rest. The foliage was green and
much larger than the surrounding
orowth. Upon examination the
thrifty plants were found to have a
large number of nodules on their
roots. These nodules were found to
no lacking on the yellow, unthrifty
nlants. There apparently was not a
sufficient number of bacteria in the
soil to inoculate more than a few of
the plants with the notwithstanding
bacteria.
Artificial methods of incubation
NAV be used on ground that has
never before grown alfalfa. Soil on
which alfalfa has previously been
grown is drilled in with the seed at
the rate of from 200 to 500 pounds
per acre. 1t Is often necessary to dry
and pulverize the infected earth be-
fore it can be mixed with the seed or
run through the drill. This work
should be done in darkened room
as exposure to light for a short time
will destroy the nodule-forming bac-
terra. The plan of broadcasting in
fected soils gives good results when
the ground is thoroughly covered
Either this method, when thorough
or that of drilling will insure results.
The soil must be drilled in with the
seed. Pure cultures of nOdule-form-
ing bacteria may be secured from the
United States department of agricul-
ture. These pure cultures come in
hermetrically sealed tubes and null
tlply rapidly when placed in water
containing certain nutriments. A
large number of seed may be inocu-
lated with a small quantity of the ma
terial. The bacteria will spread from
the few plants in the newly seeded
fields to the entire field within we T
or two without other effort on the
part of the grower If the land is we'll
MANFRED each fall and cultivated
both in the fall and spring. FIELDS
that have been in alfalfa for two or
more years were found TO be well in
oculated with nodule-forming bac-
terra.
The diminishing yields from the
older fields were found to be due
~ to poor cultivation or lack of cul
ovation altogether; ca to the lack
OF fertilization; and 90 to the
crowding of the plants the first year,
the stand being too thick in many
cases. The stand, of course, grows
thinner each year.
The old alfalfa fields should be cuI-
fivated al least twice each year, once
IN the fail and again IL. the spring. a
thorough cultivation in the fall lo0s-
ems the ground so that the winters
n'oisture can penetrate deeply into
the soil. The spring cultivation con-
serves the moisture for the use of
the plants during the growing sea-
son and at the same time destroys the
weeds. A double cultivation with
either disk or alfalfa renovator, fol-
loweG by drag harrow, is necessary
TO accomplish this result.
Few crops draw as heavily upon
the resources of the soil as does al
lalfa. For this reason it is abso-
lutely necessary to put back onto the
land some sort OF fertilizer, if good
Yields are to be maintained. IT IL
true that the alfalfa plant with the
assistance of the Notwithstanding bac-
lerla Is able to take some Of its nitro
gen from the air. Nevertheless II
draws on the potassium, phosphorus
and lime of the soil as heavily as dc
o'her cultivated crops. The appllca-
uon Of eight or 10 tons of barnyard
manure per acre before each fall cul-
ovation in many instances will double
the yield.
IL seems to be the general impress
SION that from IL to Is pounds OF
analfa seed is necessary to insure d
sood stand AS a result the plants
are USUALLY tOO thinlx tO give the pest