Grazing Management Effects on Aeschynomene Seed Production

Autor: L. E. Sollenberger, S. B. Linda, C. J. Chaparro
Rok vydání: 1991
Předmět:
Zdroj: Crop Science. 31:197-201
ISSN: 1435-0653
0011-183X
DOI: 10.2135/cropsci1991.0011183x003100010045xa
Popis: Aeschynomene (L.) is a warm-season annual legume; to persist from year to year, its stands must regenerate from seed. Autumn grazing management must balance the need for seed yield with livestock needs for quality herbage. Aeschynomene was grown in pasture association with ‘Floralta’ limpograss [ (Poir.) Stapf & C.E. Hubb.] on a Pomona sand (sandy, siliceous, hypothermic Ultic Haplaquod) in 1987 and 1988. Our objective was to measure the influence of three postgrazing stubble heights (SH) and four closure dates (CD, the times when autumn grazing was discontinued) on legume pod yield and amount of herbage left ungrazed at season end. Aeschynomene pod yield per plant and per hectare decreased as SH decreased from 24 to 8 cm, and as CD was delayed from 1 wk before to 2 wk after first flower. Ungrazed plots yielded 350 and 500 kg of pod ha in 1987 and 1988, while the earliest CD and tallest SH treatment yielded 90 and 180 kg ha. Pod yield declined with delayed CD because inflorescences per plant, pods per inflorescence, and pod weight decreased. Most pod yield components tended to decline with decreasing SH, but no significant differences were detected. Though pod yields were highest with early CD and tall SH, ≈50% of total herbage produced for these treatments remained ungrazed at season end. Thus, contribution of aeschynomene is reduced during a time when perennial grasses do not meet the nutrient requirements of grazing animals. Because taller SH leaves more ungrazed herbage, a potentially useful compromise between high seed yield and maximum forage utilization is to graze aeschynomene closely (8−16 cm), but to end autumn grazing before flowering. Additional utilization may be possible if grazing is resumed after most pods are mature, but nutritive value of this later herbage generally is low.
Databáze: OpenAIRE
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