Nutrient Management Program

Forage Grasses

General information

UF/IFAS fertilization and liming recommendations are advisory in nature and emphasize efficient fertilizer use and environmentally sound nutrient management without losses of yield or crop quality.
It is assumed the nutrients will be supplied from purchased commercial fertilizer and the expected crop yields and quality will be typical of economically viable production.
Growers should consider UF/IFAS recommendations in the context of their entire management strategy, such as return on investment in fertilizer and the benefits of applying manure or biosolids to the land.

Bahiagrass, establishing new plantings

Fertilizer rates

	Target pH	lbs/acre/cropping season
		N	P₂O₅			K₂O
Soil test			Low	Med	High	Low	Med	High
Bahiagrass	5.5	80	40	25	0	80	50	0

Fertilizer timing

Apply 80 lbs N/ac in two split applications.
- Apply 30 lbs N/ac, all the P₂O₅, and 50% of the K₂O as soon as plants have emerged.
- Apply the remaining 50 lbs N/ac and the remaining K₂O between 30 and 50 days after the initial application.

Fertilizer sources

If manure or biosolids are used as the main source of nutrients, apply the entire annual rate once the plants are large enough to withstand physical damage from the application.

Bahiagrass, grazed

Fertilizer rates

	Target pH	lbs/acre/cropping season
		N	P₂O₅			K₂O
Soil test			Low	Med	High	Low	Med	High
Bahiagrass
High N option	5.5	160	*	0	0	*	*	0
Medium N option	5.5	100	*	0	0	*	0	0
Low N option	5.5	50	*	0	0	0	0	0

*The P and K recommendations for this crop are discussed below.

Soil Test	Tissue Test	P Recommendation
P Med/High	No tissue test	0
P Low	P ≥ 0.15%	0
P Low	P < 0.15%	25 or 40 lbs P₂O₅/ac

*Recommended rate of P₂O₅ depends on nitrogen option chosen.

Bahiagrass is probably the most widely used planted forage grass in Florida. It responds well to grazing management
and inputs such as fertilization. However, it also can persist and give satisfactory yields under low inputs. Because of the
wide range of possible use and management levels, recommendations for bahiagrass fertilization differ with the level
of management and the economic inputs. Management decisions concerning liming and fertilization of bahiagrass
pastures are very sensitive to cattle productivity and prices.

Liming

In order to obtain maximum fertilization efficiency, soil pH should be maintained at 5.5 or higher. If soil pH tests below
5.3 or lower, a lime requirement test will be conducted and a recommendation for lime application will be made.
Optimal use of lime is to apply at least 3–6 months prior to fertilization to provide adequate time for the lime reaction
to occur and the soil pH to adjust to the desired level. Soils should be tested for pH every 2–3 years.

Phosphorus Fertilization

In order to receive phosphorus fertilizer recommendations for established bahiagrass, soil and tissue samples should
be submitted to the ESTL at the same time. As per the preliminary research findings, soil tests alone were not
found to be adequate to determine bahiagrass P needs. A companion tissue test has therefore been added to the
testing procedures along with the soil test to determine the P fertilization needs. Producers are strongly encouraged
to simultaneously test soil and tissue samples if bahiagrass pastures have not received P fertilization for long periods.
Phosphorus should not be applied if tissue P concentrations are at or above 0.15%, even if soil tested Low in P. For
Medium and High soil P levels, P application is not recommended since there is no added benefit of P fertilization on
bahiagrass yields.

If P recommendations are not desired and the producer is only interested in either the test for soil pH and lime
requirement recommendations, or the test for soil pH, lime requirement, K, Mg, and Ca recommendations,
the soil sample alone can be submitted to the ESTL. In this case, the soil test report will not include P fertilizer
recommendations.

Both the consolidated representative soil and the tissue samples should be collected simultaneously from each field
of up to 40 acres. The testing procedures and the recommendations for P for bahiagrass may be adjusted as field research data become available.

Maintenance Fertilization of Established Bahiagrass Pasture

Four fertilization options are presented below for bahiagrass pastures. Choose the option that most closely fits
your fertilizer budget, management objectives, and land capability. If you will only be grazing your bahiagrass, you
should carefully consider the potential for economical return on your investment in fertilizer before using the
Medium-Nitrogen or High-Nitrogen options described below. The added forage produced for grazing animals may
not be worth the added cost.

Low-Nitrogen Option. Do not use this option if you cut hay, because nutrient removal by hay is much greater than
by grazing animals. This option results in the lowest cost of purchased fertilizer. Apply 50 to 60 lbs N/ac in the early
spring to maximize much-needed forage. Do not apply K recognizing that N will be the limiting nutrient in this
low-cost option. Apply 25 lbs P₂O₅/ac if your soil tests Low in P and tissue P concentration is below 0.15%. Do not
apply P if tissue P concentration is at or above 0.15%, even if the soil tests Low in P. For Medium and High soil P levels,
neither P application nor tissue analysis is recommended because there will be no added benefit of P fertilization on
bahiagrass yields.

Medium-Nitrogen Option. Apply 100 lbs N/ac in the early spring. Apply 25 lbs P₂O₅/A if your soil tests Low in P and
tissue P concentration is below 0.15%. Do not apply P if tissue P concentration is at or above 0.15%, even if the
soil tests Low in P. For Medium and High soil P levels, neither P application nor tissue analysis is recommended
because there will be no added benefit of P fertilization on bahiagrass yields. Apply 50 lbs K₂O/A if your soil tests Low
in K and none if it tests Medium or High.

High-Nitrogen Option. Apply 160 lbs N/ac in two applications of 80 lbs N/ac in early spring and early summer. Apply 40 lbs
P₂O₅/ac if your soil tests Low in P and tissue P concentration is below 0.15%. Do not apply P if tissue P concentration
is at or above 0.15%, even if the soil tests Low in P. For Medium and High soil P levels, neither P application nor
tissue analysis is recommended since there will be no added benefit of P fertilization on bahiagrass yields. Apply 80 lbs
K₂O/ac if your soil tests Low in K and 40 lbs K₂O/ac if it tests Medium. No K should be applied if your soil tests High in
K. The fertilization rates suggested in this option are high enough to allow bahiagrass pasture to achieve well above
average production. Management and environmental factors will determine how much of the potential production
is achieved and how much of the forage is utilized. A single cutting of hay can be made without need for additional fertilization.

Bahiagrass Cut Sometimes for Hay

For a Single Cut per Year from Pastures. If you used the Low-N option of pasture fertilization, apply 80 lbs N/ac no
later than six weeks before the growing season ends. Apply 50 lbs K₂O/A if your soil tests Low in K and none if it tests
Medium or High. Apply 25 lbs P₂O₅/ac if your soil tests Low in P and tissue P concentration is below 0.15%. Do not
apply P if tissue P concentration is at or above 0.15%, even if the soil tests Low in P. If you used the Medium-N option
of pasture fertilization, apply an additional 80 lbs N no later than 6 weeks before the growing season ends. Apply 50
lbs K₂O/A if your soil tests Low in K and none if it tests Medium or High. Apply 25 lbs P₂O₅/ac if your soil tests Low
in P and tissue P concentration is below 0.15%. If you used the High-N option of pasture fertilization, you do not need
any additional N fertilization to make one cut of hay. Apply 80 lbs K₂O/A if your soil tests Low in K and 40 lbs K₂O/A if it
tests Medium. Apply 40 lbs P₂O₅/A if your soil tests Low in P and tissue P concentration is below 0.15%.

Bahiagrass Grown Only for Hay

For Multiple Cuts of Hay. Apply 80 lbs N/ac in early spring. Also in spring, apply 80 lbs K₂O/ac if your soil tests Low in
K and 40 lbs K₂O/ac if it tests Medium. Apply 40 lbs P₂O₅/A if your soil tests Low in P and tissue P concentration is
below 0.15%. Apply an additional 80 lbs N and 40 lbs K₂O/A after each cutting, except the last in the fall. Include 20 lbs of
P₂O₅/ac after each cutting if the soil tested Low in P.

Bahiagrass for Seed Production

Apply 60–80 lbs N/ac in February or March. At the same time, apply 80 lbs K₂O/ac if your soil tests Low in K and 40
lbs K₂O/A if it tests Medium. Apply 40 lbs P₂O₅/ac if your soil tests Low in P and tissue P concentration is below
0.15%. Graze until May, June, or July, depending on variety. Remove cattle before seed heads start to emerge and apply
an additional 60–80 lbs N/ac.

If the bahiagrass is not grazed, do not apply fertilizer in February or March because this may stimulate excessive top
growth. Mowing from February to April may be needed to remove excessive top growth. Apply 60–80 lbs N/ac before
seed heads first appear. Apply 25 lbs P₂O₅/A if your soil tests Low in P and tissue P concentration is below 0.15%. Do not
apply P if tissue P concentration is at or above 0.15%, even if the soil tests Low in P. For Medium and High soil P levels, neither P application nor tissue analysis is recommended. Apply 50 lbs K₂O/A if your soil tests Low in K and none if it tests Medium or High. Fertilize Pensacola in March/April and Argentine and Paraguay in May/June.

Limpograss (Hemarthria)

Fertilizer rates

	Target pH	lbs/acre/cropping season
		N	P₂O₅			K₂O
Soil test			Low	Med	High	Low	Med	High
Limpograss	5.0	120	20	0	0	40	20	0

Fertilizer timing

Establishing new plantings:
- The N recommendation for new plantings is 100 lbs/ac.
- Apply 30 lbs N/ac, all the P₂O₅, and 50% of the K₂O as soon as plants have emerged.
- Apply the remaining K₂O and 70 lbs N/ac 30 to 50 days later.
Maintenance fertilization of established pastures:
- For grazed, established stands, apply 60 lbs N/ac and all the P₂O₅ and K₂O in late winter or early spring.
- Apply an additional 60 lbs N/ac in late summer or early fall.
- For a minimum fertilization alternative, ignore the P and K recommendation and apply only 60 lbs N/ac per year.
Making hay, silage, or green chop
- Apply 80 lbs N/ac and all the recommended P₂O₅ and K₂O in late winter or early spring.
- Apply an additional 80 lbs N/ac and 40 lbsK₂O/ac after each cutting, except the last in the fall.
- If the soil tested low in P, include 20 lbs P₂O₅/ac in the fertilizer applied after each cutting, except the last in the fall.

Fertilizer sources – Special note if applying manure or biosolids

A different set of economic factors is usually considered when waste materials rather than purchased fertilizer are supplying the nutrients.
It is often impractical to follow the application timings discussed above when using waste materials from other operations.

Hay or Silage (Perennial Grass)

Fertilizer rates

	Target pH	lbs/acre/cropping season
		N	P₂O₅			K₂O
Soil test			Low	Med	High	Low	Med	High
Hay or silage	5.5	*	80	60	0	80	60	0

*The N recommendation is discussed below.

Fertilizer timing

For Multiple Cuts

Apply 80 lbs N/ac and all of the recommended P₂O₅ and K₂O in early spring. Apply an additional 80 lbs N and 40 lbs
K₂O/ac after each cutting, except the last in the fall. Include 20 lbs of P₂O₅/ac in the supplemental fertilizer if the soil
tested low or medium in P.

For a Single, Late Season Cut from Pastures

If you have not applied N in the past 2 months, apply 80 lbs N/ac and the soil-test recommended amount of P₂O₅ and
K₂O. If you have applied N in the past 2 months, do not apply any N now, but do apply the soil-test recommended
amount of P₂O₅ and K₂O. Any application of fertilizer should be made no later than 6 weeks before the growing
season ends.

Special Note If Applying Manure or Biosolids

A different set of economic factors is usually considered when waste materials rather than purchased fertilizer are
supplying the nutrients. Additionally, it is often impractical to follow the application timings discussed in this footnote
when using waste materials from other operations.

References

CIR 1152 UF/IFAS Standardized Fertilization Recommendations for Agronomic Crops

Other Resources

Nutrition and Fertilization of Forage Crops