VOL. LXIX
INDIANAPOLIS, APRIL 25, 1014
4#
NO. 17
Soy Beans and Cow Peas for Soil Improvement
If I had to write the eleventh commandment so it would cover the greatest number of farming sins, it would
be this: Thou shalt grow sufficient
legumes to maintain the supply of nitrogen  and  organic  matter in  the  soil.
It seems strange that some allow
their soil to become hard, compact,
lifeless, badly deficient in organic matter and almost devoid of nitrogen,
when  all   of  these  conditions  may   be
How to Grow and Manage These Valuable Crops
for the Greatest Benefit to the Farm.—By J. C. Beavers
wheat follows clover or beans. (This
rotation is widely known as one that
maintains the soil in a high state of
productivity.) In 1884 Hellriegel and
Willarth, two German scientists, found
that  leguminous plants  did  gather  ni-
acre, to contain in top and root from
100 to 130 pounds of nitrogen. The
data concerning which of the two crops
contains the most nitrogen is somewhat conflicting but usually the crop
that  thrives  best in  a  particular  local-
down in very poor physical condition.
Of course, the ideal way of improving
the physical condition of any soil, when
it is possible to do so economically, ls
to use those crops that will add large
quantities of both organic matter and
nitrogen. The available data Indicate that there are few crops that are
so well suited for this purpose as soy
beans and cowpeas. These crops
may   be   grown   from   the   Great  Lakes
A Field of Soy Beans as They  Should  be Grown.
prevented by the proper use of legumes
cm the farm. Yet, there are millions
of acres in the southern states and
hundreds of thou.sands in the northern
states that have been so reduced in
fertility that they are agriculturally
unprofitable, because sufficient legumes
have not been grown or because not
enough of those grown has been turned
under.
Throughout the corn belt, and in
fact in most of the territory north of
the cotton belt, clover has been and
mo doubt will continue to be the principal leguminous crop. But in this territory th( e are many large areas of
thin sandy and clay soils that for various reasons will not grow clover. On
such soils cow peas and soy beans are
rapidly becoming important crops, just
as they have been in the south for
many years.
Value of Ijeguines Known to Romans.
That beans, vetches, or lupines were
the best preparation for a wheat crop
was common knowledge of Roman agriculture, and the same observation
afterwards led to the formation of the
Norfolk  four-course rotation   In  which
trogen from the air, but only when, by
infection from the soil, certain characteristic nodules were found upon the
roots. While this discovery was made
nearly thirty years ago, its significance
in general agriculture is just beginning
to  be  appreciated.
The present wide spread and rapidly
increasing culture of soy beans and
cow peas is due to their ability to
thrive upon thin soils and to improve
their productive capacity. The main
part of this improvement is undoubtedly due to the large quantity of nitrogen added. The Indiana Experiment
Station found that cow peas grown as
a cover crop after wheat made an average for three years of 7.1 tons of
green forage per acre which contained
112 pounds of nitrogen. The stubble
and roots from the same crop contained 16.8 pounds of nitrogen to the acre.
Soy beans grown under the same conditions produced 6 tons of green forage per acre which contained 92
pounds of nitrogen, while the stubble
and roots contained 13 pounds. Judging from this data we may expect a
crop of soy beans or cow peas that
produces   2   tons  of  cured  hay   to   the
ity will produce the greater amount of
forage per acre and give the greater
amount  of  .soil improvement.
The Question of Nitrogen and  Humus.
At present there is no way of determining how much nitrogen the plant
gets from the soil or air, but it is usually estimated that these crops when
grown under normal conditions, will
gather about two-thirds of their nitrogen from the air. On this basis a
crop capable of making two tons of
cured hay to the acre would gather
from the air from 8 to 12 dollars
worth of nitrogen. There is much
evidence to show that the turning under of such a crop gives marked improvement. One farmer in southwestern Indiana reports an increase of
20 bushels of wheat to the acre from
turning under one crop of cow peas on
run-down  sandy soil.
While nitrogen is an important element to be considered when selecting
crops to be used for manuring, it is
not the only one. In certain cases
organic matter may be of as much
benefit to the soil as nitrogen. This ls
particularly   true   on   soils   badly   run
to the Gulf and will thrive on a greater variety of soils and under more adverse conditions than any other of
our common leguminous crops. I have
yet to learn of a soil that is so badly-
run down that it will not grow one or
the other of these crops when reasonable   attention  is  given   to  its  culture.
The .Effect of Ijeguines on Thin Soil.
Wherever they have been grown on
thin soils, marked improvement in the
productivity of other crops has been
noted. At the Alabama Station cotton waa grown on one plat in 1898
and on an adjoining plat, cow peas
were grown. Thecowpeas were picked
by hand and yielded 11.8 bushels
per acre. The following spring the
vines were turned under and both plats
were planted to cotton. The plat which
had been in cow peas the previous
year made 367 pounds more seed cotton per acre than the one which grew
cotton the previous year. In order to
find out how much residual effect the
cow peas would give, both plats were
put in oats in 1910. Oats on the plat
which had grown cow peas produced
Continued on page 20.