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SWEET LUPINS PROMISING FOR ALABAMA FARMERS
MONROEVILLE, ALA.__--Sweet lupin may provide a double boost in the future
to Alabama farmers, according to Alabama Agricultural Experiment Station
researchers. The legume crop produces grain that can be fed without
processing to livestock, and at the same time leaves up to 90 pounds
of nitrogen per acre for subsequent crops.
Randy Akridge, superintendent of the Monroeville Experiment Field, noted
that full season white lupin has performed well in tests at the Auburn
University research facility. "This is just our third year working
with lupine, and we have produced yields of 35-40 bushels per acre,"
Akridge said.
Lupin can be crushed on the farm and fed to livestock without the need
for processing, giving it a big advantage over soybeans and other grains.
It typically has about 35 percent protein, compared to 42 percent for
soybeans. High quality lupin also contains about 10 percent oil, and
all these attributes combine to make it a good protein supplement for
livestock rations.
Wayne Reeves, an agronomist with the U.S. Department of Agriculture's
Agricultural Research Service and adjunct Experiment Station researcher,
has worked with lupin at several locations in Alabama. Though enthusiastic
about the crop's potential, Reeves cautions that it has many problems
to overcome before it can be grown, even on a limited scale, by Alabama
farmers. Reeves pointed out that a multidisciplinary group of researchers
in Auburn's Ag Experiment Station, including plant breeders and plant
pathologists, are already involved in the lupin project. "We think
the winter hardy, or full season lupin, will ultimately be the choice
in Alabama. Currently only one variety, TiftWhite-78, can be grown here,
but it is not available to growers because of susceptibility to Phytophora,
Pythium, Sclerotium rolfsii and a number of other soilborne diseases,"
Reeves noted.
Alabama was once a part of the lupin belt, but this was bitter lupins
used solely for ground cover and to build nitrogen. These contain alkaloids
that produce a bitter taste to animals, making them unacceptable for
livestock feeds. Consecutive freezes and curtailment of government programs
ended lupin production in Alabama in the early 1950s.
Reeves' initial interest in lupin was as a nitrogen-producing legume,
but since the 1930s, plant breeders were able to genetically remove
the bitterness, and new sweet lupin varieties produced seed highly palatable
to livestock. Thus, his interest in developing production practices
for sweet lupins with the dual use as a nitrogen fixer, and as a highly
nutritious feed for livestock.
Winter hardy sweet white lupine was planted at the Monroeville Field
in early November. "We have learned that the variety of lupin we're
growing won't tolerate wet soil, and we have had problems with damping-off
disease in young plants," Akridge commented. A subsoiler was used
in the November 1990 planting and seed were planted directly into the
raised rows. Thirty-inch row spacings on these raised rows has greatly
reduced early diseases, and subsequent slow growth problems, according
to the Auburn University researcher.
In addition to winter hardy full season sweet lupin, which are planted
in late October and November and harvested in early June, Auburn researchers
are looking at spring lupines, which are planted in February and March
and harvested in late June. This is the first year of testing the two
spring varieties, Ultra and Primorsky. Planting dates for these varieties
were timed to come after the last days of 24, 28 and 32 degree F temperatures,
or Feb. 7, Feb. 14 and March 14. The Auburn researchers are skeptical
that the spring varieties can be planted early enough to get in the
needed 130 days to seed set before daytime temperatures reach the mid
1980s, at which time seed development ceases.
Akridge explained that planting date is critical, because lupins are
susceptible to cold temperatures during two growth stages: shortly after
emergence and during bloom. For full season lupins this should not be
a problem in south Alabama. Lupin's cold hardiness is documented by
the full season variety at the Monroeville Field, which survived 15
degree F. cold in February with no damage. However, winter is usually
Alabama's rainiest season, which adds drainage problems and increases
disease woes.
In tests so far, researchers have used 30- to 36-inch rows, though tests
have been conducted on row spacings as narrow as seven inches. Planting
depth is critical with lupins, according to Akridge. "The seed
don't seem to be able to handle planting more than an inch deep. They
come up, but they seem to use all their energy getting out of the ground,
and simply don't continue to grow," Akridge explained.
Despite the many problems in growing lupin, the opportunity far outweighs
these disadvantages, according to Reeves. "In the South, we spend
about $68 million annually on nitrogen fertilizer to grow wheat. Heavy
rainfall during the time fertilizers are applied to wheat contribute
heavily to it being an inefficient user of nitrogen (N), which can lead
to heavy concentrations in runoff, leading to environmental problems.
Lupin produces its own nitrogen, with some left over for rotation crops.
Lupin also grows well on poor soil, because it requires no N and little
other residual fertilizers. But its biggest advantage is that it can
be grown, crushed on the farm and fed directly to livestock. In Alabama,
where most feed grain is brought in from other states, and both the
poultry and beef cattle industries are growing, a new feed source for
livestock, plus the double dividend of nitrogen, makes lupins look promising
indeed.
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By:
Roy Roberson
April 1, 1991
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