Establishment of Warm-Season Perennial Pastures with Forage Mixtures

May, 2018
 Dr. Joe Vendramini, UF/IFAS Range Cattle Research & Education Center, Ona

Establishment of new pastures and hayfields is one of the most costly management practices in forages and livestock operations. It is estimated that the cost to establish a warm-season perennial grass in Florida is approximately $ 600.00/acre. In addition, a detrimental factor in establishing new forage fields is the extended time required for the grass to fully establish and be productive; which can take from 2-6 months.

Bahiagrass has been the most used forage for grazing in Florida due to its persistence under low-input systems. However, it has been observed that it may take from 6-12 months to have a fully established bahiagrass pasture after seeding. Besides the lack of forage production during the establishment time, the slow establishment of bahiagrass gives the opportunity for weeds to encroach and may increase the cost of establishment due to additional weed control. The presence of weeds in newly established bahiagrass pastures is particularly problematic because there are no herbicides recommended for newly established bahiagrass. Other warm-season perennial grasses, such as the Mulato II, also have slow establishment, which may incur in similar problems.

Warm-season annual grasses has not been extensively cultivated in South Florida due to short growing season and difficult management in the summer. However, warm-season grasses, such as sorghum and millet, have fast establishment and superior forage nutritive value and may be a valuable forage resource during periods of shortage of forage.

Recently, some species of warm-season annual legumes have been tested in South Florida. Cowpea and sunnhemp are legumes with fast establishment and superior nutritive value; however, they are not persistent under grazing.

Therefore, a research project was conducted from April to September 2017 to collect preliminary data about mixing warm-season perennial and warm-season annual forages during the establishment of warm-season perennial pastures. The experiment was conducted at Ona, FL and treatments were:

  • Cayman Brachiaria (warm-season perennial grass)

  • Cayman Brachiaira + Sorghum Sudangrass + Sunnhemp (1/2 seeding rate)

  • Cayman Brachiaira + Sorghum Sudangrass + Sunnhemp (Full seeding rate)

Full seeding rates were 10 lb/acre Cayman, 25 lb/acre Sorghum Sudangrass and 25 lb/acre sunnhemp. Plots were harvested every 6 weeks after seeding.
The mixture at half seeding rate had the greatest annual herbage accumulation (Figure 1). The sorghum and sunnhemp were the major portion of the forage production in the first harvest, while the brachiaria was the only forage species left in the third and fourth harvest. The half mixture produced 75% greater herbage accumulation than the Cayman treatment. In addition, the forage produced in the first harvest had the greatest crude protein concentration.

Herbage Accumulation Chart

 

Botanical Composition Chart

 

Table 1.  Crude protein of plots established with different forage species
Treatment Harvest 1 Harvest 2 Harvest 3 Harvest 4
CP (%)
Cayman - 11.1 11.9 15.1
Mixture Half 20.5 10.1 12.9 16.2
Mixture Full 21.8A 13.1 12.5 15.2

Table 2.  In vitro organic matter digestibility of plots established with different forage species
Treatment Harvest 1 Harvest 2 Harvest 3 Harvest 4 SE
  IVDOM (%)  
Cayman - 60 55 55 2.8
Mixture Half 68 61 55 58 2.8
Mixture Full 66 64 58 5 2.8

 

 

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