UT Beef and Forage Center

Grazing Management

Winter grazing stockpiled native warm-season grasses in the Southeastern United States
In the Southeastern United States, native warm-season grasses (NWSG) are not harvested during autumn to rebuild root reserves, resulting in de facto stockpiled winter forage. Senesced NWSG forage is considered nutritionally inadequate by temperate livestock managers, but comparable forage is regularly utilized in rangeland systems. This experiment compared the forage characteristics of two NWSG pastures: switchgrass [Panicum virgatum L. (SG)] and a two species mixture of big bluestem/indiangrass [Andropogon gerardii Vitman/Sorghastrum nutans L. (BBIG)] to tall fescue [Festuca arundinacea Schreb. (TF)].

Native Grasses

Management of Native Warm-Season Grasses for Beef Cattle and Biomass Production in the Mid-South USA
Native grasses, such as switchgrass, big bluestem, indiangrass, and eastern gamagrass may be capable of providing desirable summer forage for cattle as well as a source of biomass for renewable energy
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Profitability of Beef and Biomass Production from Native Warm-Season Grasses in Tennessee
Native warm-season grasses (NWSGs) have demonstrated potential to reduce summer forage variability, and furthermore, there has been growing interest in the use of NWSGs as lignocellulosic biomass crops. The objective of this research was to determine if there was a difference in net returns for full-season summer grazing beef steers on three NWSGs.

Forage Harvest Timing Impact on Biomass Quality from Native Warm-Season Grass Mixtures
Biomass production systems using native warm-season grasses can allow for an early-season harvest (for forage) followed by a dormant harvest (for biomass). This study was conducted to investigate the impact of harvest timing and grass species on the chemical composition of harvested forage and biomass.

Biomass and Integrated Forage/Biomass Yields of Switchgrass as Affected by Intercropped Cool- and Warm-Season Legumes
Switchgrass has potential as a biofuel feedstock for ethanol production on marginal soils not suitable for row crop production. Further, it is hypothesized that legumes may be interseeded into switchgrass to increase available soil nitrogen (N) and enhance switchgrass yields. Therefore the primary objective was to identify compatible legume species for intercropping with lowland switchgrass and determine if biomass yields and forage quality can be improved.

The Cost of Feeding Bred Dairy Heifers on Native Warm-Season Grasses and Harvested Feedstuffs
The objectives of this research were to determine the cost of feeding bred dairy heifers grazing native warm-season grasses (NWSG), with and without legumes, and compare the cost of grazing with the cost of rearing heifers using 3 traditional rations. The 3 rations were corn silage with soybean meal, corn silage with dry distillers grain, and a wet distillers grain-based ration. Results of this study suggest that SG was the most cost-effective NWSG alternative to harvested feeds for bred dairy heifer rearing.

Switchgrass Yield and Stand Dynamics from Legume Intercropping Based on Seeding Rate and Harvest Management
Intercropping legumes may reduce inputs and enhance sustainability of forage and feedstock production, especially on marginal soils. This approach is largely untested for switchgrass production, yet producer acceptance should be high given the traditional use of legumes in forage/agricultural systems. Intercropping selected legumes in switchgrass may enhance forage quality and yield while reducing nonrenewable inputs, fertilizer costs, and emissions/runoff to air and groundwater.

Dormant-Season Planting and Seed-Dormancy Impacts on Switchgrass Establishment and Yield
Establishment failures linked to seed dormancy are a challenge to wide-scale use of switchgrass (Panicum virgatum L.) for biomass feedstock and forage production. One prospective strategy for breaking dormancy is dormantseason planting.

Displacing Inorganic Nitrogen in Lignocellulosic Feedstock Production Systems
Legume intercrops (partridgepea) and biochar may supply analogous N to synthetic fertilizers, thereby displacing inorganic N without altering feedstock quality. However, for inorganic N alternatives to be competitive on a break-even cost basis, greater biomass yields need to be obtained under these management practices.

Breakeven Price of Biomass from Switchgrass, Big Bluestem, and Indiangrass in a Dual-Purpose Production System in Tennessee
Producers considering a dual-purpose production system for NWSGs will be confronted with several complex decisions about how to manage yield, quality, and cost of replacing nutrients while maximizing profits.

The Impact of Harvest Timing on Biomass Yield from Native Warm-Season Grass Mixtures
With increased harvest opportunities native warm-season grasses, grown in the mid-South United States under a dual-harvest system, can increase harvest options for producers by supplying acceptable forage yield for both early harvests and still provide biomass production.

Fertilization

Alternatives to Conventional Nitrogen Fertilization on Tall Fescue and Bermudagrass
Alternatives to conventional N fertilization on tall fescue and bermudagrass were studied at the University of Tennessee.
The objective of this study was to evaluate the effect of different sources of N, to include two perennial and one annual legume species, on HM and forage nutritive value of tall fescue and bermudagrass pastures.

Nitrogen Rate and Initiation Date Effects on Stockpiled Tall Fescue During Fall Grazing in Tennessee
In Tennessee, N is one of the most common limiting nutrients for tall fescue production. Rising prices for N fertilizer have pressured cow-calf producers in Tennessee to reevaluate N management alternatives. The objectives of this study were to determine the effect of initiation date and N fertilization on stockpiled tall fescue yield, nutritive value, animal performance during fall grazing, and overall profitability of the production system.

Forage Performance and Soil Quality in Forage Systems under Organic Management in the Southeastern United States
Interest is increasing in organic forage production and sod-based rotations in the southeastern United States, but research-based information is limited. A replicated field study was established to evaluate productivity and soil quality changes in five organically managed forage systems.

Cultivar and Phosphorus Amendment Impacts on Organically Managed Forage Cowpea Yield and Composition
Cowpea is a warm-season legume with many traits that make it an attractive forage or cover crop for organic systems. Eight cowpea cultivars were evaluated under organic management at two locations for stand establishment, forage yield and quality, and weed biomass.

Forage Management

Forage Warm-Season Legumes and Grasses Intercropped with Corn as an Alternative for Corn Silage Production
The purpose of this study was to determine the yield and nutritive value potential of warm-season annual forages intercropped with corn (Zea mays L.) for silage production. Intercropped forages can be harvested and ensiled with corn for silage production or can be left with the corn residue after harvesting to be grazed on in integrated crop-livestock systems.

Influence of Height-Based Management on Forage Nutritive Value of Four Warm-Season Forage Grasses
Harvest timing is an influential factor in providing animals with high quality forage. Height-based management is commonly practiced to determine timing of cutting or grazing. This study aimed to observe nutritive value changes in tall- and short-growing warm-season grasses with repeated cuttings.

Forage Nutritive Value and Herbage Mass Relationship of Four Warm-Season Grasses
To provide animals with high quality forage, practical methods are needed to estimate nutritive value to optimize harvest timing. The objective of this study was to develop such models to estimate warm-season forage nutritive value in the southeastern United States.

Effects of Aminocyclopyrachlor Plus Metsulfuron on Tall Fescue Yield, Forage Quality, and Ergot Alkaloid Concentration
Most tall fescue in the United States is infected with a fungal endophyte that produces ergot alkaloids that are harmful to livestock and contribute to fescue toxicosis. Because the alkaloids are concentrated in seed and stems, a potential way to reduce the likelihood of fescue toxicosis is by suppressing seedhead formation with herbicides.

Utility of Aminocyclopyrachlor for Control of Horsenettle and Tall Ironweed in Cool-Season Grass Pastures
Because horsenettle and tall ironweed are difficult to control in cool-season grass pastures, research was conducted in Tennessee and Kentucky in 2010 and 2011 to examine the efficacy of aminocyclopyrachlor on these weeds.

Influence of Aminocyclopyrachlor Plus Metsulfuron on Seed Head Development and Forage Quality in Tall Fescue
When applied alone or in combination with MAT28 or aminopyralid, metsulfuron reduced seed heads and improved forage quality in tall fescue, but also caused injury and reduced spring yield. Also, metsulfuron applied alone or in combination with MAT28 or aminopyralid reduced total ergot alkaloid concentration and therefore can potentially reduce the severity of fescue toxicosis.