Imperial Valley press., 1922-10-04
VALLEY TURNING (
TO COVER CROPS
TO BETTER SOIL
Velvet Beans, Clover In
Demand; Legumes
Improve Soil

At the present time when many
| rHEclicIs of Imperial Valley are turn
| ing their attention to soil improvement
| by planting crops which will replace
d supply of nitrogen in the soil, 9th
crs are hesitating to follow out such
| a program, believing it unnecessary.
| That turning under crop of alfalfa
or other leguminous growth is bound
to enrich the land, is a fact that is well
known to horticultIlists, and indeed
| has been praeticed in China and other
countries for cent? rics.
One of the best oil-improving crops,
| both for soils which are naturally un-
| fertile and for those which have become
somewhat exhausted, by long cultiva-
| ton, is the velvet bean, of which there
| are many varitics. They are Wig
orous growing legume, the vines often
reaching a length of more than 50 feet.
The ability of this plant to make a
profitable growth Oh land so poor that
most legumes Will not thrive, places it
among the most important crops for
soil cnriching. In addition to adding
large quantities of vegetable matter to
the soil at Il minimum. cost, thus max
ing il more rctentive of moisture, the
n0duics on the rots collect Il large
amount of nitrogen from the atmos-
phcre. This nitrogen will be left in
the soil when the crop is turned under
and the plants decay. Even though
the ciop is grazel. the nitrogen and
humus content of the soil will be great
ly increased, us much of the nitrogen
n the portions of tho plants CONSUMED
by the stcch will be voided I;y turn
lng under Il crop of velvet beans the
fertility of the land will be so I'M
proved that others crops may be grown
more successfully. The yield of seed
from suah ground is usually heavier
than from fields which have been too
long in cultivation without a rcpienish-
ing of the lifegiring nitrogen. Many
experiments lave been conducted to
determine the value of velvet beans as
a soilimprovIng crop, all of which
have proved successful.
Sweet Clovnr Good
Another soil-improV.HG ernp is sweet
clover. Unlike many legumcs, sweet
clover will make a good growth on
soils too depleted in humus for profit
able crop production. In its ability to
grow and to produce II considerable
quantity of forage on such soils, it
viii add much humus to them, The cx-
tensive root systems do much toward
breaking up the subsoil, thereby pro
viding better aeration and drainage.
The effect of the large, deep roots in
opening up the subsoil and providing
better drainage is often very noticeable
in the spring as the land upon which
sweet clover has grown will be in
condition to plow earlier than the ad-
iacent fields where it has not bee..
grown.
The roots are very often one eighth
of an inch in diameter at a depth Of
three feet and they decay in five to
eight weeks after the plants die. The
holes left by the roots are left partly
filled with fiji brous substance which
permits rapid drainage. Sandy soils
are benfited materially by the addi
tion of humus and nitrogen, while hard
pan often is broken up so completely
that alfalfa or other crops will readily
grow on the land. The roots add much
organic matter to the layers Of sol;
below the usual Gcpth of plowing, while
those in the surface sml, together with
the stubblc and stems, when the crop
is plowed under add more humus than
possibly any other lcgume which may
be grown in short relations. Not only
does this crop add organic matter to
the SOIL but in common with other le-
gumes, it has the power of fixing at
mospheric nitrogen by means of the
nitrogen gathering bacteria in the
nodules on the roots.
Tue ability of sweet clover to re
claim abandoned, run down land has
been demonstrated in northern kca
lucky and Alabama. In these regions
many farms were so depleted in nitro
gen and humus by continuous cropping
with nonlogunlinous crops that profit
able yields codl,l be nbta:heu No longer
Through the use of this crop, many o:
hcse farms have been brought back t..
an excellent state of fertility.
Annual yellow sweet clover is rapidly
gaining in favor as grcen-nlanurc
crop for orchards IN the Southwest
The use of annual sweet clover for this
purpose has also increased very rapid
lv in southern Califomia in recent
years and this increase apparently has
been justified by the results obtained
with it. 1t should De remembeit itd that
sweet clover will not make a salts
factory growth on acid soils and that
il is very essential to provide innecula-
ion il the soil is not innoculated al.
| ready
To- i.,,1 mis- L nv nC-