Forage Systems for the Southeastern United States: Crabgrass and Crabgrass-Lespedeza Mixtures

Crabgrass is a warm-season annual species that has the potential to provide high-quality summer forage for ruminants in the transition zone between subtropical and temperate regions of the United States. Growing annual lespedeza in association with crabgrass may be beneficial due to nitrogen transfer from the legume to the grass. The objectives of the research reported in this thesis were to (1) determine the effects of pH on establishment and growth of crabgrass; and (2) evaluate the effects of lespedeza seeding rate and N fertilization treatment on the yield, botanical composition, and nutritive value of crabgrass-lespedeza mixtures. A greenhouse study was conducted using three soil pH levels of 4.8, 5.5, and 6.3. Crabgrass germination and root and shoot yields were not affected by soil pH values. A field study was conducted to evaluate the influence of six lespedeza seeding rates (0-28 kg ha-1) and two N fertilization treatments (140 kg total N ha-1 or zero N) on crabgrass-annual lespedeza mixtures. In most cases, increasing lespedeza seeding rate increased lespedeza in the sward. However, lespedeza rate had limited effect on yield and nutritive value of the mixture. Nitrogen fertilization increased crabgrass in the sward and total yield by as much as 46%. Responses of nutritive value parameters to N fertilization were variable and appeared linked to weather factors. In vitro true digestibilities ranged from 750 to 875 g kg-1, and were largely unaffected by N fertilization and seeding rate The results of these studies indicate that crabgrass could provide moderate amounts of highly digestible forage while growing on acidic soils commonly found in the southeastern United States. Annual lespedeza may be grown in association with crabgrass, but limited improvement in yield and nutritive value were found for this practice.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Crop and Soil Environmental Sciences

Department dc:contributor.department

Crop and Soil Environmental Sciences

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2005

Author dc:creator

• Aleshire, Emily Browning

Chair dc:contributor.committeechair

• Teutsch, Christopher D.

Committee members dc:contributor.committeemember

• Alley, Marcus M.
• Abaye, Azenegashe Ozzie
• Thomason, Wade E.

• botanical composition
• Digitaria
• Kummerowia striata
• crabgrass
• seeding rate
• soil pH
• grass-legume mixtures
• nitrogen fertilization
• Kummerowia stipulacea
• annual lespedeza

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-07272005-141340

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/34206