The silver star., 1897-11-25

M Uultliu OF. Ht
summary is as fol-
lows:
Cow peas, clovers. vetches and other
plants, known as leguminous plants or
legumes, when plowed under enrich
the soil by adding nitrogen. a large
proportion OF which they have obtain
tained from the atmosphere.
The engagements or tubercles on the
roots are the means by which the free
nitrogen of the air is made available to
ieguminous plants. II these tubercles
are wanting on leguminous plant, the
nitrogen OF the air is unavailable to
that plant. just as it is to cotton. grass.
and all other higher plants that are not
| leguminous.
On some soils these normal tubercles
do not develop on the roots of such le-
gumes as have never before been grown
in that locality. The growth OF tub
ercles can be induced by adding GER
tain germs to the soil. a process which
is called inoculation.
In Alabama the COW pea is the most
generally satisfactory renovating plant
for summer growth. There is also need
for winter growing leguminous plants.
such as hairy vetch and crimson Glow
er, to occupy the land in winter be-
tween two sale crops, in order to de-
crease washing and teaching of the
soil and to add vegetable matter rich
in nitrogen.
Hairy vetch. without fertilizer. yield
ed On field where this plant had been
repeatedly grown 17.765 pounds of
green forage, or AHA pounds OF hay
per acre.
On field where hairy vetch had
never before been grown and where
the fertilizer applied contained phos-
phoric acid and potash, but no nitro
gen, the yield was only 235 pounds OF
hay per acre; on an adjoining and sim
liar plot, the seed for which were in
oculated with earth from an old vetch
field. the yield Of hay was 2.54O pounds.
an increase Of 995 per cent following
treatment which cost nothing except
a small amount of labor. On the in
oculated plot the plants were well sup
piled with tubercles. while on the plot
not treated the plants were bare OF
tubercles.
A germ fertilizer, intended to make
available the free nitrogen OF the air
by inducing the growth Of tubercles on
legumes grown in soils not already
stocked with the proper forms of germ
life. was purchased in Germany and
used In Auburn in pot experiments
with hairy vetch. Canada field peas and
crimson clover.
incubation with this germ fertilizer
or nitrogen greatly increased the yields
Of all of these plants as compared
with untreated plants.
This increase In the weight Of in
oculated plants. after thorough dry
ing, was as follows:
Hairy vetch. increased by SO per
cent.
Canada field peas. increased by 1888
per cent.
Crimson clover young plants). In
creased by 146 per cent.
I.upins (tested on only one soiD. not
increased.
Germ fertilizer prepared for vetch.
was effective on Canada field peas.
Iuoculation material procured with
out cash outlay acted like nitrogen.
and greatly increased the yields Of
hairy vetch and alfalfa.
Soil from field where a given Ie-
guminous plant has recently been sue
cessfully grown Is an effective inocula-
ting material for the same kind Of
plant when first sown In soil not al
ready naturally supplied with the re-
quired form Of germ life.
The dust adhering to the seed OF bur
clover was an effective inoculating
material for alfalfa; the increase in
the first cutting Of alfalfa hay follow
ing this incubation was 1886 per cent.
Inoculation for COW peas and lesped-
eza was apparently unnecessary In the
soils used In these experiments. In or
near all Of these soils these two plants
have been growing for years. Hence
we may infer that these soils have been
previously inoculated Dy germ-laden
dust or by some other natural agency.
In soil which for many years had
borne no leguminous plants. tuberclea
developed without Intentional inocula-
tion on hairy vetch. Canada held peas,
crimson clover and lupins. ~ well q
on COW peas and lespedexa. This soil
was more nearly independent Of In
ocuiation than any other soil tested,
and yet even on this soil the increase
In the weight Of inoculated plants over
plants not inoculated was ss per cent.
with hairy vetch 81 per cent. with Can
ada neld peas and 70 per cent with
crimson clover.
Many soils are naturally inoculatsd
M regards the most commonly grown
lcguminous plants and hence are not
pcr rcfited by artificial incubation.
ngos- ~ out the ssn J0~s Scale.
Bulletin SS. Alabama Experiment
Station: In the inspection Of various
nurseries made In Alabama this sprins
l . ~Hl l-A