|Newman, Y - UNIV OF FL|
|Sollenberger, L - UNIV OF FL|
|Boote, K - UNIV OF FL|
|Hall, M - UNIV OF FL|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 1, 2004
Publication Date: February 28, 2005
Citation: Newman, Y.C., Sollenberger, L.E., Boote, K.J., Allen Jr, L.H., Vu, J.C., Hall, M.B. 2005. Temperature and carbon dioxide effects on nutritive value of rhizoma peanut herbage. Agronomy Society of America, Crop Science Society of America, Soil Science Society of America Meeting.v 45, p. 316-321 Interpretive Summary: The impact of climate change on nutritive value of forages could be important for livestock productivity. USDA-ARS and University of Florida scientists determined the effect of increasing temperature and carbon dioxide (CO2) on nutritive value of both leaves and stems of rhizoma perennial peanut, an important forage of the lower southeastern USA. In vitro digestible organic matter (IVDOM), neutral and acid detergent fiber (NDF and ADF), and lignin were determined in plants grown in two levels of CO2 (360 and 700 PPM) and four temperatures (Gainesville ambient temperature, ambient + 2.7; ambient + 5.4; and ambient + 8.1 degrees Fahrenheit). Leaf nutritive values were not affected by either CO2 or temperature. Also, stem nutritive values were not affected by CO2. However, stem IVDOM declined slightly with increasing temperature, and stem NDF, ADF, and lignin increased slightly with increasing temperature. In conclusion, for this forage legume, the overall nutritive value decreased with increasing temperature, but nutritive value was relatively unaffected by CO2. Combining this information with prior studies in Gainesville, decreases in nutritive value can be offset by forage yield increases in rising CO2.
Technical Abstract: The impact of climate change on nutritive value of forages can be as important as the impact on total production. The objective was to determine the effect of increasing temperature and carbon dioxide (CO2) on leaf and stem composition and digestibility of rhizoma perennial peanut (Arachis glabrata Benth.). In vitro digestible organic matter (IVDOM), neutral and acid detergent fiber (NDF and ADF), and lignin concentrations were determined for plants grown during two years in two levels of CO2 (360 and 700 PPM) and four temperatures in temperature-gradient greenhouses (baseline, or ambient temperature, B; B + 1.5; B + 3.0; and B + 4.5 Celsius). Neither CO2 nor temperature affected leaf IVDOM, but stem mean IVDOM declined with increasing temperature from 562 (in B) to 552 g per kg in B + 4.5) in Year 1 and from 577 to 511 g per kg in Year 2. Stem mean NDF increased with increasing temperature from 556 to 561 g per kg in Year 1 and from 519 to 526 g per kg in Year 2. Stem ADF (412 to 418 g per kg) and lignin (80 to 93 g per kg) increased linearly as temperature increased in year 2 only. For this forage legume, the nutritive value decreased with increasing temperature, but it was relatively unaffected by CO2.