Effects of N Fertilization Rate on Estimates of Rumen Degradable Protein for Bermudagrass Forages.
(C06-coblentz895391-poster)
Authors:
J.E. Turner - University of Arkansas W.K. Coblentz - University of Arkansas R.K. Ogden - University of Arkansas J.L. Gunsaulis - University of Arkansas M.B. Daniels - University of Arkansas
D.A. Scarbrough - Northwestern Oklahoma State University K.P. Coffey - University of Arkansas
K.A. Teague - University of Arkansas
Abstract:
Common bermudagrass [Cynodon dactylon (L.) Pers.] was harvested from two producer sites (Latta and Stephens) in 2000 to assess the effects of nitrogen (N) fertilization on concentrations of rumen degradable N in bermudagrass forages. Ammonium nitrate was applied in split applications (28 April and 19 July) at rates totaling 0, 56, 112, 168, 224, 280, or 336 kg ha-1 of actual N. Forages were harvested three times (30 May, 7 July, and 18 August) over the growing season. When expressed on the basis of total plant dry matter (DM), rumen degradable N increased linearly (P = 0.0001) with N fertilization at both sites on the 30 May and 18 August harvest dates. A quadratic effect (P = 0.0003) also was observed on the 18 August harvest date at the Latta site. No carryover effects of the initial fertilization treatment were observed at either site for the second harvest. Similar effects were observed when rumen degradable N was expressed on the basis of total forage N; concentrations increased linearly (P less than 0.0038) on the first and third harvest dates at both sites. For rumen escape N expressed on the basis of total forage DM, concentrations increased linearly (P less than 0.0024) with N fertilization for the 30 May and 18 August harvest dates at the Stephens site and on the 18 August harvest date at the Latta site. Estimates of rumen degradable N ranged from 416 to 643 g kg-1 N over the entire study, and were improved by N fertilization.
Speaker Information: Wayne Coblentz, University of Arkansas, B107B AFLS Department of Animal Science, Fayetteville, AR 72701; Phone: 479-575-7914; E-mail: [email protected]
Session Information: Tuesday, November 4, 2003, 4:00 PM-6:00 PM Presentation Start: 4:00 PM (Poster Board Number: 512)