Alternative Stategies for Pasture Renovation
Pasture renovation has been defined as the improvement of a pasture by partial or complete destruction of the sod, plus liming, fertilizing, weed control, and seeding, in order to re-establish desirable forage plants. In Florida, pasture renovation usually means complete destruction of the existing plants or sod and replanting with a new or improved perennial grass species. A producer may decide to simply replace an existing pasture grass with a new improved grass because of the higher yield and quality of the new grass, but most renovation is done because the existing pasture has deteriorated to the point that forage production is greatly reduced. Renovation provides opportunities to fill in bull holes, control weeds, incorporate lime if needed, and establish a superior forage.
Renovation programs are usually started in the spring or fall. Primary cultivation should be done with a moldboard plow or a heavy cutting disk. Turning the soil with a moldboard plow may have an advantage in that it buries a lot of weed seeds deep enough that they cannot germinate and be a problem in the new planting. Secondary tillage can be accomplished with a finishing disk and drag to level and smooth the soil surface.
Several strategies for pasture renovation can be followed:
- A producer may choose to start in the fall by plowing and
planting a cool-season annual forage and then establishing the new
permanent pasture grass the next summer. Planting and growing an annual
grass is expensive; therefore, a producer should plan to use the forage
for stockers, heifer development, or as a supplement for calves in an
early-weaning program. Plowing deep, disking, and seeding of the winter
annual, followed immediately by firm-rolling may all be done on the
same day. The purpose of these practices is to bury the old sod and
weed seed while preserving soil moisture for successful establishment
of the winter crop. The winter annual will also smother germinating
warm-season weeds in early spring but provide residual fertilizer to
the next crop. As production of the winter annual declines in spring ,
the field is disked about four times during April and May before
planting the new permanent pasture grass at the beginning of summer
rains in June.
- Another strategy for seedbed preparation that is
especially useful in peninsular Florida is to plow and disk during the
months of April and May--usually a dry period. Most of the existing
plants can be killed through desiccation. Three or four diskings spaced
over two months may be necessary to kill all of the old plants. When
the summer rains start, the new permanent pasture grass can be planted.
- When planting some forages, it is desirable to plow the
old sod in the fall (November-December) and then plant in late winter
or early spring. This practice is useful for the establishment of
sprigged bermudagrasses or perennial peanut and for early plantings of
bahiagrass or rhodesgrass. With this practice there may be some concern
for soil loss due to wind erosion if there are prolonged periods of dry
weather. Disking could be delayed until close to the planting date in
order to reduce wind erosion. Often there is concern about bahiagrass
seeds that are in the soil and the possibility that bahiagrass might
invade the new planting, which may be especially important when
attempting to establish a pure stand of an improved bahiagrass such as
Tifton-9 or a hybrid bermudagrass for hay production.
- Farmers might choose to plant the area with cultivated row
crops or vegetables for one or more seasons, which helps eliminate
bahiagrass seeds as well as the old established plants and builds up
soil fertility.
- A forage producer may choose to plant an annual forage
crop in order to accomplish the same purpose. Pearl millet or
sorghum-sudan hybrids can be planted in the spring or early summer. In
the fall the land could again be disked and planted to a cool-season
forage crop such as ryegrass or rye. Two annual crops with accompanying
cultivation for seedbed preparation should put the land in fine shape
for the establishment of the new pasture the following year.
- Some producers may choose to use herbicides in their
renovation program. In order to kill the old sod, herbicide should be
applied while the plants are green and growing. Roundup® or a similar
herbicide may be especially useful where there are spots of common
bermudagrass. Common bermudagrass can be especially difficult to
control. If all of the vegetative growth is killed, there may still be
seed in the soil to re-infest an area. Some producers who have a solid
stand of common bermudagrass have simply chosen to fertilize and graze
it. Before deciding to use a herbicide in a renovation program, a
producer must consider the cost.
- After the lifting of grass sod or moderate mole cricket damage, a closely grazed or mowed bahiagrass pasture can be successfully regenerated by rotovating to distribute remaining sod followed by firm-rolling. In south Florida, this is best done between February and March when cool temperatures prevent rapid desiccation of the field and some rains are normally expected. The field is fertilized as soon as sprouting occurs.
