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Copyright 2005, Board of Trustees, University
Indian River Field Laboratory Mimeo Repurt IRL 68-1 *-*
S1 PLANTING INFORMATION ON S. HUMILIS
S~APR 2 2 1968
Albert E. Kretschmer, Jr.:/
SI.F.A.S. Univ. of Florida
S. humilis is a self-regenerating annual summer legume tha-h-grw-ewwe-
in peninsular Florida. It competes well with pangolagrass that has not been
fertilized with nitrogen. Information is not available on its growth with other
Florida grasses at this time.
A University of Florida Agricultural Experiment Station Circular will be
in print within two months and will give a more detailed report than the
following information. The legume has been tried successfully during the past
5 summers on a small commercial basis and the following information is based
on observations of these plantings and on research at the Indian River Field
Seeds planted after the last frost and before the middle of June begin
to flower in September or early October. Some mature seeds should be produced
by November 1, if grazing is deferred or decreased during September and October.
The growth rate is rapid from June till flowering. Plants are killed easily by
frost. Mature seeds produced in the fall germinate the following spring.
Volunteer stands have been good in south Florida especially when maximum seed
production is permitted the previous fall.
Cowpea inoculant should be used at 2 to 3 times recommended rates in a
manner similar to that for white clover (wet seeds with a molasses-water
mixture, etc. and mix inoculant with moist seeds).
Because of the hook on each seed pod, seed distribution is difficult.
Mixing the inoculated seed with cottonseed meal or other finely ground material
has facilitated seed distribution. Seeding rates of 2 to 5 pounds of unhulled
seeds per acre are satisfactory.
It is suggested that the seeds be planted at the same time as the grass;
or that the permanent grass sod be disked or cross-chopped prior to seeding to
weaken but not kill the grass. Rolling or dragging the area after seeding
should help in establishment. Soil preparation after the first year has not
been needed in south Florida.
I/ Agronomist, Florida Agricultural Experiment Stations, Indian River Field
Laboratory, P. 0. Box 248, Fort Pierce, Florida.
LIME AND FERTILIZER
Because of the diverse soil types in Florida it is difficult to make
recommendations for all soils. The following guide should be helpful, however.
S. humilis can grow well with soil pH values at or below those normally recom-
mended for white clover and alfalfa. On flatwoods type soils the following
guide should be used:
Virgin: Minimum of 1 ton of lime per acre and minimum 400 pounds per acre
of 0-12-12 or 0-14-14.
Following Fall or Spring Vegetables: No lime or fertilizer except possibly
potash (use soil test information).
White Clover-Grass: Maintain lime and fertility for best clover growth.
No additional fertilizer needed for S. humilis.
General: Soil pH about 5.5 or above and soil test information to determine
phosphorus and potassium levels.
Succeeding Years: About 300 to 400 pounds of 0-10-20 per acre per year
in grass pastures. Apply in spring when seedlings are visible. Do not
use nitrogen as grass competition may become too great.
Initial year: Graze the area about 2 months after seeding or when plants
are 6 to 8 inches high. If grass growth appears to be competing with S. humilis
seedling growth, graze earlier. Continue to graze or rotationally graze until
September and then remove cattle until the first frost or until sufficient mature
seeds have been produced. Normally, the heavier the grazing during the summer
the later flowering commences in the fall. It is important to obtain good seed
yields the initial year especially when plant populations are poor or not uniform.
Normally, however, grazing is recommended during the summer to prevent too much
Succeeding years: Normal grazing management can be used after the initial
year. In the spring if it appears that the grass is going to "out-grow" the
volunteer S. humilis seedlings graze the area as heavily as needed to remove
the initial flush of grass. S. humilis can withstand heavy grazing. It is
generally better to graze the young plants at least once early than to permit
the plants to attain a height of more than about one foot and then heavily graze.
In the former instance, the plants will branch out with some shoots close to the
ground, and in the latter instance, some of the plants may be killed prior to
1. Grazing -- continuous and or fall-deferred.
2. Hay -- after grazing until August or September there will be enough S. humilis
and grass growth to permit taking a hay crop after the first frost or after
sufficient mature seeds have been produced.
3. Cover crop -- S. humilis has been used successfully, on a limited scale, as
a cover crop in citrus groves.