|
|
||||||||
USDA-ARS, Appalachian Farming Syst. Res. Cent., 1224 Airport Rd., Beaver, WV 25813
* Corresponding author (dbelesky{at}afsrc.ars.usda.gov)
Received for publication July 3, 2001. Cool-season forages dominate pastures in the Appalachian region where midsummer weather conditions often depress productivity. Warm-season forages can buffer variation in available herbage, but land resources may limit the area dedicated to special-use crops. A replicated field plot experiment was conducted for 3 yr (19951997) in a bermudagrass (Cynodon dactylon L.) stand oversown with Kentucky bluegrass (Poa pratensis L.) and white clover (Trifolium repens L.) to determine the influence of defoliation on productivity, nutritive value, and botanical dynamics of the mixture. Botanical composition changed with defoliation and varied among years. Bermudagrass comprised as much as 55% of the sward in mid- and late-season 1995. By 1997, the proportion was similar to other grasses and rarely exceeded 20%. Maximum instantaneous growth rates occurred later in the growing season in 1995 when bermudagrass was a dominant sward component compared with subsequent years when bermudagrass was <10% of the sward. Rates in 1995 were greatest for swards clipped at 6-wk intervals (70 kg ha-1 d-1) or when 20-cm tall and least when clipped at 2-wk intervals (33 kg ha-1 d-1) and at 10-cm height (45 kg ha-1 d-1). The trend was reversed by 1997 when sward composition shifted away from bermudagrass to cool-season grasses and white clover. Yields were greatest when cool-season species dominated the sward. Creating a self-regulating mixture of warm- and cool-season perennial forages may be a means of achieving some stability in sward productivity and might be useful where wide fluctuations in growing conditions occur among years.
Abbreviations: ADG, average daily gain IGR, instantaneous growth rate IVOMD, in vitro organic matter disappearance S50, 10-cm canopy clipped to 5-cm residue T75, 20-cm canopy clipped to a 5-cm residue 2WK, clipped at 2-wk intervals to a 5-cm residue 6WK, clipped at 6-wk intervals to a 5-cm residue
This article has been cited by other articles:
![]() |
A. Deak, M. H. Hall, M. A. Sanderson, and D. D. Archibald Production and Nutritive Value of Grazed Simple and Complex Forage Mixtures Agron. J., May 11, 2007; 99(3): 814 - 821. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. A. Cassida, C. B. Stewart, V. A. Haby, and S. A. Gunter Alfalfa as an Alternative to Bermudagrass for Pastured Stocker Cattle Systems in the Southern USA Agron. J., May 3, 2006; 98(3): 705 - 713. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. P. Belesky Regrowth Interval Influences Productivity, Botanical Composition, and Nutritive Value of Old World Bluestem and Perennial Ryegrass Swards Agron. J., February 7, 2006; 98(2): 270 - 279. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| The SCI Journals | Crop Science | Vadose Zone Journal | |||
| Journal of Natural Resources and Life Sciences Education |
Soil Science Society of America Journal | ||||
| Journal of Plant Registrations | Journal of Environmental Quality |
The Plant Genome | |||