Limpograss Sod Management and Aeschynomene Seed Reserve Effects on Legume Reestablishment
- C. J. Chaparro,
- L. E. Sollenberger and
- C. S. Jones
Aeschynomene (Aeschynomene americana L.) is a warm-season, annual legume that is well adapted to wet habitats. Stands must regenerate from seed each year, so size of seed reserve and management of the associated grass in winter and spring are important. In 1988 and 1989, effects of aeschynomene soil-seed reserve (simulated by broadcasting known quantities of seed in the pod) and winter-spring management of a limpograss [Hemarthria altissima (Poir.) Stapf and Hubb.] sod on legume reestablishment were evaluated on Smyrna (sandy, siliceous, hyperthermic Aerie Haplaquods) and Pomona (sandy, siliceous, hyperthermic Ultic Haplaquods) sands. All combinations of three tillage procedures (no disking, disking in spring, or disking in early summer) and two grazing treatments (grass grazed to a 10-cm stubble or not grazed) were allocated as main plots in a split-plot arrangement. Subplots were four quantities of seed applied the previous December (20, 60, 180, and 540 kg ha−1). Dry weather in late spring and early summer 1988 reduced grass competition to legume seedlings that had established in April, and grazing had no effect on percentage legume (PCL) in harvested forage. Within each disking treatment, PCL increased linearly with size of seed reserve, but summer disking reduced legume contribution relative to spring and no disking. With near optimal rainfall in 1989, PCL for the grazed swards was three to six times greater than for ungrazed swards. For all disk treatments, PCL increased linearly with size of seed reserve, but spring disking was superior to no disking and summer disking. Results suggest that aeschynomene reestablishment in limpograss is favored by spring disking and grazing limpograss until legume seedlings are 5 to 8 cm tall. Using this management in 1988 and 1989, seed reserves of 25 to 135 kg ha−1 were needed for successful aeschynomene reestablishment.
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