Managing Cover Crops Profitably - Valley Crops Home

screening, a number of farmers have been evaluating
balansa in trials covering an even wider geographic
area.
For further information, contact:
Seth Dabney
USDA-ARS National Sedimentation Lab.
P.O. Box 1157
Oxford, MS 38655-2900
(662) 232-2975; dabney@sedlab.olemiss.edu
Bell bean (Vicia faba)
Other common names: fava bean, faba bean,
small-seeded horse bean.
Type: Winter annual or spring annual legume.
Description: Stems coarse, upright; leaves compound,
usually with six broad leaflets and no tendrils;
dark purple extrafloral nectary on lower
surface of stipule; flowers large, white, with dark
purple blotches;pods large,cylindrical,containing
six to eight seeds.
Bell bean is a true vetch,but differs greatly from
other vetches with its strong, upright growth. It
also has a relatively shallow, thick taproot, which
may be useful for opening up heavy soils. Bell
bean often is used in mixtures with vetches, peas
and/or cereals. Because of its height and because
it does not tolerate close mowing, it often is omitted
from mixtures in frost-prone areas. It is best
adapted to Hardiness Zones 8 and 9.
Bell bean is frequently infested by the pea-bean
aphid, which seldom affects its use as a cover
crop. The aphid, which does not attack grapes,
and the presence of extrafloral nectaries, may
attract beneficial insects into vineyards. However,
their effects on insect and mite management have
not been tested.
Bell bean is more susceptible to frost damage
than other vetches. It is very similar in growth to
broad bean (also known as Windsor or horse
bean), which has a much larger, flat seed. The
smaller seed size of bell bean makes it more economical
to sow.
Bell beans grow quickly throughout the winter
in California, add N—although less than other
vetches—and provide a tall structure to support
twining vetches and peas. Bell beans do not
spread like vetches and they have no hard seed.
They are easily incorporated into the soil.
Estimated amount of N fixed may range from 50-
200 lb/acre, but bell bean is regarded as a low
nitrogen fixer in southern California. In six weeks
of growth,bell bean may fix up to 100 lb/acre and
a total of up to 150 lb/acre on fertile soils.
Seed 1 to 3 inches deep at 80-200 lb./A. Faba
bean can grow on a wide range of soils, from
loams to clays, and under a variety of drainage
conditions.It does not tolerate saturated soils,and
extended drought, especially at flowering,
reduces seed production drastically.
Bell beans are not drought tolerant. They are
easier to control than other vetches.Bell beans do
not tolerate close mowing.
—Chuck Ingels
University of California Extension
4145 Branch Center Rd.
Sacramento, CA 95827-3898
(916) 875-6913; FAX: (916) 875-6233
caingels@ucdavis.edu
Black oats
Black oats (Avena strigosa) is the No. 1 cover
crop on millions of acres of conservation-tilled
soybeans in southern Brazil. In the temperate
farming regions of southern South America, black
oats owes its popularity to a number of factors. It
is very resistant to rusts and produces large
amounts of biomass, similar to rye. It has exceptional
allelopathic activity for weed control. It is
easy to kill mechanically and cycles nitrogen better
than rye.
Black oats breaks disease cycles for wheat and
soybeans and is resistant (some research claims
even suppressive) to root-knot nematodes. On
top of this, it is also a good forage. It is not cold
tolerant.
One cultivar, IAPAR-61, a public release developed
by the Paraná State Agricultural Research
Service, has been investigated by USDA-ARS and
was grown in 1997 in Alabama and Georgia for
commercial seed production. Its use likely will be
restricted to the lower southern Coastal Plain
(Zones 8b, 9 and 10). Seed should be available
commercially in limited amounts in 1998.
—D.W. Reeves (see p. 161)
UP-AND-COMING COVER CROPS 159