The Wilmington morning star., 1945-10-22
s0YBEANS DISPLAY
STARVATION SIGN.

MANY soybeans, particularly
sose in the Upper Coastal Plain,
Wv. wv showing starvation signs for
do foods this year. The farmer
an recognize these signs of de-
ss;encv symptoms quite easily by
Nv w. unusual following and dying of
.as leaves on his plants.
pu+ To make matters even worse,
=. W |. Nelson, agronomist with
No Agricultural Experiment Sta.
s;nn at State college, points out that
sor every acre of soybeans that
.hows these outward signs of star
s ' there are many other acres
Not have no visible symptoms but
aavertheless are suffering from
liant Of one or more of the plant
foods.
The average yield of soybeans in
North Carolina is approximately 10
sushels per acre. Even at the pres
ant market price these low yields
cannot be very profitable. While
Yields have been greatly reduced
i some sections this season be-
a.rse of the continued rains, the
nsual reason for the low yields is
lack OF plant food.
This plant starvation is brought
about because the use of fertilizer
an soyheans is not common prac-
~+bor,,oora y,oncf - <l> n..,
beans are grown in rotation with
corn, a crop which frequently re-
ceived but little fertilizer or lime.
This past season, DR.. Nelson
saws, many fields of beans have
shown a dark yellowing of the
leaves particularly between the
veins. And now as combining time
approaches, the soybeans in these
fields have shed their leaves some.
what earlier than normal. This con-
dition is brought about by lack
Of magnesium in the soil.
In other fields soybeans have not
had their usual dark green color.
This is due to a lack of nitrogen.
Soybeans are legumes and there
fore fix most of their nitrogen from
the air with the aid of nodule bac-
terra on the roots. Under acid soil
conditions, however, the bacteria
cannot work efficiently and the soy
beans will suffer from nitrogen de-
ficiency.
Dolomitic limestone remedies
both of these troubles. It furnishes
magesium to feed the plant and
1t makes the soil less acid thereby
rendering conditions more favor
able for the nodule bacteria. Counts
Of nodules this year on several ex-
periments showed that soybeans
grown on lined land had twice as
many nodules as those beans grown
on unlimed land.
1t is possible to spread too much
lime on the land, however. In over
lined soils, the manganese be-
comes unavailable to the plant be-
the leaves turn bright yellow be-
tween the veins This condition on
the site of old lime piles is well
known to soybean growers.
1t would be well to determine
how much lime the 1916 soybean
fields need and apply it this winter,
DR.. Nelson says. The lime require
ment can be determined by send
ing soil sample to the Soil Test
ing Division of the State Depart
ment Of Agriculture. Sample boxes
and sampling instructions may be
obtained from county agents.
In experiments conducted on a
Norfolk loamy sand in Wilson
County in 1914 lining proved prof
table. A broadcast application of
dolomitic limestone increased the
yield OF soybeans 10 bushels per
acre.
The fact that most growers are
not fertilizing their soybeans with
potash is strikingly evident this
year, particularly in the Upper
Coastal Plain where the majority
Of the soybean fields are showing
potash hunger signs on the leaves.
Ihese signs are recognized by a
yelloWing of the edges of the upper
leaves with these edges later turn
ing brown and the whole leaf dy-
ing, In extreme cases the plant
growth is limited.
IN soils not quite so low in po-
lash the soybeans may attain full
growth but the field of beans is
low In fact, common complaint
OF soybean growers is that the
plants grow large enough but the
PODS shed off. Pod counts were
made periodically at several loca.
uons the past two years and they
revealed that 40 to 60 percent Of
lne pods shed in September. Auuli-
eauons of potash reduced this she'd
ding
on test plot in Beaufort County
4ocated on soil very low in po-
saSh' 100 pounds of muriate Of po-
laSh 100 pounds K2O) increased the
ylelo Is busiest per acre. Quality
was also greatly improved.
LII conclusion, DR.. Nelson says,
oeaAS grown on very dark soil
s ~ higher in potash yielded
uu bushels per acre with no potash.
WIN l2O pounds of muriate side
dressed, the yield was increased to
Is bushels per acre