Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: December 1, 2002
Publication Date: February 1, 2003
Citation: BARTHOLOMEW, P.W., WILLIAMS, R.D. PRELIMINARY STUDIES OF SELF-SEEDING WARM-SEASON LEGUMES FOR LOW-INPUT FORAGE PRODUCTION. AMERICAN SOCIETY OF AGRONOMY MEETINGS. 2003. p. 67. Technical Abstract: The quality of feed available from warm season grass pastures in the Southern Great Plains declines through the summer months. Incorporation of warm season legume forage into feeding systems could mitigate the decline in grass feed quality, and possibly extend the forage growing season. In low-input farming systems, resources for cultivation and reseeding are often not available. Two self-seeding warm season forage legumes, Korean lespedeza (Lespedeza stipulacea) and Verano stylo (Stylosanthes hamata), were studied in field and growth chamber experiments to evaluate their usefulness for low-input pasture-based farming systems. In field trials Lespedeza established easily on clean-tilled ground but ground cover by Stylo was slow and the crop was unable to compete effectively with regrowing natural pasture species. Both species grew slowly when oversown in natural pasture, but production of Lespedeza was significantly than that of Stylo. Seed deposition of Lespedeza following a single harvest in fall was 6600 seeds.m-2 in 2001 and 19700 seeds.m-2 in 2002. Regrowth of Lespedeza harvested in late-July dropped an average of 3600 seeds.m-2 by late-fall. Stylo seed deposition was 141 seeds.m-2 in 2001, but in 2002 there was no measurable seed output. Germination rate of Lespedeza was similar at day/night temperatures of 15/15, 22.5/15 and 30/15 degrees Celsius. Stylo, in contrast, showed an increased germination rate as temperature increased over the range 15-30 degrees Celsius. At a constant 15 degrees Celsius, Stylo is close to its minimum temperature for germination. Lespedeza and Stylo grown in a growth chamber at 30/15 degrees Celsius day/night temperatures showed no difference in growth rate or response to two light regimes over a period of 4 weeks following seedling emergence. The lower temperature requirement for germination of Lespedeza means that it can germinate earlier in the spring than Stylo and this probably confers a competitive advantage over warm season grasses.