Everglades Station Mimeo Report EES65-22 April 1965
T&y Fertilize That Pas u? e
F., H. Thomas' K -
The most obvious answer to this question is to increase the forage production
so that animal gains and/or stocking rates per acre may be increased. This may be
the prime reason for fertilizing a pasture but it certainly isn't the only major
reason. Plants, like animals,'need.a well-balanced ".diet" to produce satisfactorily
When plants are kept in a.healthy condition, they may better '"fight-off" attacks of
disease, insect and weed intrusions. Healthy plants withstand cold weather better
than unhealthy plants and recover from freeze damage much quicker. These factors
are very important in.determining .net profits. A drop in forage.produced by lack
of fertilization is not the only loss. It costs money to fight weeds, diseases
and insects after they gain.a "toe-hold" in a pasture. Also, these pests reduce
the feed value of the forage by.taking away some of the plant's nutrients. This
is important to the health and production of the animals as well as the plants.
There are numerous management decisions that a rancher must make each year.
One such series of.decisions is when will a pasture be fertilized,-what kind and
how much fertilizer will be used during-the next year or even two to three years.
It takes time and, money to establish new pastures and time to bring a low-producing
pasture up to its maximum. You can't fertilize today and expect to realize maxi-
mum benefits tomorrow or next week.
The Everglades Experiment Station assists the rancher in making decisions on
fertilizing.his"pastures by. operating a soil testing laboratory. The soil samples
from his pastures are.analyzed in the laboratory and recommendations are made,
based on research conducted by the staff members. In order to make a reliable re-
commendation, the soil sample should represent the pasture. From research findings
we recommend that the pastures on organic soil be sampled to a depth of 5 to 6
inches in at least three locations. These locations within the pasture should be
selected as average areas judging by topography and grass growth. Be sure to avoid
all detectable urine and mature spots. Submit the samples to the soil testing
laboratory. If the field is to be established in a pasture grass, take the soil
samples as if it were for row crops. That is, take a minimum of 20 cores and com-
posite these cores into one sample and submit for analysis. For sandy soils, con-
sult your County Agricultural Agent on sampling procedure and submit the samples
through him to send to a soil testing laboratory.
-/ Assistant Chemist, Everglades Experiment Station, Belle Glade, Florida.
When should the fertilizer be applied? If you are utilizing the pastures
by grazing only, then we recommend fertilizing in October or early November.
This helps protect against cold weather damage plus promotes a quick recovery in
late winter and early spring. Leaching of fertilizer on organic soils is not
considered a problem. Consequently, benefits can be realized by fertilizing most
anytime during the year. Very rarely is a response obtained from nitrogen ferti-
lization of pastures on the organic soils.
Recommendations on how much phosphorus and potassium fertilizer to use are
based on soil test analysis. However, the micronutrients, copper, manganese and
zinc, recommendations are not based on soil test analysis because of difficulties
in analyzing for these elements. In virgin land, copper, manganese and zinc should
be broadcast at the rates of 15.0, 7.5 and 5.0 pounds per acre of CuO, MnO and ZnO,
respectively, and disked under to obtain a thorough mixing with the top 6 to 10
inches of soil. If this is not done before establishing a pasture, then these
elements aren't utilized very efficiently and the grass production may never be-
come as high as it would if they were plowed under. Copper is.recommended for
maintenance at the rate of 2 to 3 pounds CuO per year. Of course, even distri-
bution of the fertilizer is important.
If the forage is removed from the pasture for hay, silage or greenchop, then
fertilization must be increased to maintain these pastures. The quantities of
forage removed, frequency of removal and prior fertilization determine to some
extent how often and when to fertilize. Soil tests should be used as a guide for
how much fertilizer to use.
The specie of pasture grass also influences the rate and ratio of fertilizer
required. For example, Argentine Bahia seems to require more phosphorus than
Pensacola Bahia. It is also higher in phosphorus content, which may be desirable
from the standpoint of the cattle's nutrition.