Journal of Animal Science, Vol 79, Issue 9 2439-2448, Copyright © 2001 by American Society of Animal Science

JOURNAL ARTICLE

Effects of nitrogen fertilization and harvest date on yield, digestibility, fiber, and protein fractions of tropical grasses

C. R. Johnson, B. A. Reiling, P. Mislevy and M. B. Hall
Department of Animal Sciences, University of Florida, Gainesville 32611-0910, USA.

To evaluate the response of three tropical forage species to varying rates of nitrogen (N) fertilization [0, 39, 78, 118, 157 kg of N/(ha x cutting)] and five summer harvests, forage DM mass and nutritive value were evaluated in a randomized complete block design with a split-split plot arrangement of treatments. Plots (n = 60) were established in 1996, and five harvests were conducted every 28 d from June through September in 1997 and 1998, with fertilizer applications occuring after each harvest. Fertilization with 78 kg of N/(ha x cutting) increased forage mass in these grasses by 129% (P < 0.01) compared with no N fertilization. Additional N did not result in further increases of forage mass. Bermudagrass (Cynodon dactylon) produced more forage DM [P < 0.01; 1,536 +/- 43 kg/(ha x cutting)] than stargrass [Cynodon nlemfuensis; 1,403 +/- 43 kg/(ha x cutting)] or bahiagrass [Paspalum notatum; 1,297 +/- 43 kg/(ha x cutting)]. Peak forage mass for all species occurred in late June and July. In vitro organic matter digestibility (IVOMD) of stargrass increased (P < 0.01) linearly with fertilization. A quadratic response to N fertilization (P < 0.01) was noted in IVOMD of bermudagrass, whereas bahiagrass was not affected. Bermudagrass was more (P < 0.01) digestible (57.5 +/- 0.4) than stargrass (54.6 +/- 0.4) and bahiagrass (51.9 +/- 0.4%). As fertilization level increased, NDF decreased linearly (P < 0.01) in all three forages. Total N concentration increased (P < 0.01) linearly as N fertilization increased in all forages. Total N concentration was highest (P < 0.01) in stargrass (2.4%, DM basis) compared with bermudagrass (2.2%) and bahiagrass (2.0%). Total N concentration was depressed in all forages for late June and July harvests (P < 0.01). Fertilization increased (P < 0.05) the concentration (% of DM) of all protein fractions. In July and August, nonprotein N was reduced 11.8% (P < 0.01), whereas ADIN increased in July (P < 0.01). Bahiagrass had less N in cell contents than did bermudagrass and stargrass but had a greater concentration of N associated with the cell wall. Managerial factors, including rates of N fertilization and harvest dates, can have profound effects on the nutritional value of forage. An increased understanding of these effects is imperative to improve supplementation programs for ruminants.

This article has been cited by other articles:

				A. K. Obour, M. L. Silveira, M.B. Adjei, J. M. Vendramini, and J. E. Rechcigl Cattle Manure Application Strategies Effects on Bahiagrass Yield, Nutritive Value, and Phosphorus Recovery Agron. J., September 1, 2009; 101(5): 1099 - 1107. [Abstract] [Full Text] [PDF]

				J. L. Foster, A. T. Adesogan, J. N. Carter, A. R. Blount, R. O. Myer, and S. C. Phatak Intake, digestibility, and nitrogen retention by sheep supplemented with warm-season legume hays or soybean meal J Anim Sci, September 1, 2009; 87(9): 2891 - 2898. [Abstract] [Full Text] [PDF]

				J. L. Foster, A. T. Adesogan, J. N. Carter, L. E. Sollenberger, A. R. Blount, R. O. Myer, S. C. Phatak, and M. K. Maddox Annual Legumes for Forage Systems in the United States Gulf Coast Region Agron. J., March 4, 2009; 101(2): 415 - 421. [Abstract] [Full Text] [PDF]

				J. C. Burns, M. G. Wagger, and D. S. Fisher Animal and Pasture Productivity of 'Coastal' and 'Tifton 44' Bermudagrass at Three Nitrogen Rates and Associated Soil Nitrogen Status Agron. J., January 8, 2009; 101(1): 32 - 40. [Abstract] [Full Text] [PDF]

				J. M. B. Vendramini, L. E. Sollenberger, J. C. B. Dubeux Jr., S. M. Interrante, R. L. Stewart Jr., and J. D. Arthington Sward Management Effects on Forage Component Responses in a Production System for Early Weaned Calves Agron. J., November 7, 2008; 100(6): 1781 - 1786. [Abstract] [Full Text] [PDF]

				A. Bar-Tal, S. Landau, Z. Li-xin, T. Markovitz, M. Keinan, L. Dvash, S. Brener, and Z. G. Weinberg Fodder Quality of Safflower across an Irrigation Gradient and with Varied Nitrogen Rates Agron. J., September 8, 2008; 100(5): 1499 - 1505. [Abstract] [Full Text] [PDF]

				J. M. B. Vendramini, L. E. Sollenberger, A. T. Adesogan, J. C. B. Dubeux Jr., S. M. Interrante, R. L. Stewart Jr., and J. D. Arthington Protein Fractions of Tifton 85 and Rye-Ryegrass Due to Sward Management Practices Agron. J., February 29, 2008; 100(2): 463 - 469. [Abstract] [Full Text] [PDF]

				G. B. Huntington, J. C. Burns, and S. L. Archibeque Urea metabolism in beef steers grazing Bermudagrass, Caucasian bluestem, or gamagrass pastures varying in plant morphology, protein content, and protein composition J Anim Sci, August 1, 2007; 85(8): 1997 - 2004. [Abstract] [Full Text] [PDF]

				J. R. Kiniry, B. L. Burson, G. W. Evers, J. R. Williams, H. Sanchez, C. Wade, J. W. Featherston, and J. Greenwade Coastal Bermudagrass, Bahiagrass, and Native Range Simulation at Diverse Sites in Texas Agron. J., February 6, 2007; 99(2): 450 - 461. [Abstract] [Full Text] [PDF]

				P. A. Beck, S. Hutchison, C. B. Stewart, J. D. Shockey, and S. A. Gunter Effect of crabgrass (Digitaria ciliaris) hay harvest interval on forage quality and performance of growing calves fed mixed diets J Anim Sci, February 1, 2007; 85(2): 527 - 535. [Abstract] [Full Text] [PDF]

				D. A. Scarbrough, W. K. Coblentz, K. P. Coffey, D. S. Hubbell III, T. F. Smith, J. B. Humphry, J. A. Jennings, R. K. Ogden, and J. E. Turner Effects of Forage Management on the Nutritive Value of Stockpiled Bermudagrass Agron. J., September 5, 2006; 98(5): 1280 - 1289. [Abstract] [Full Text] [PDF]

				R. K. Ogden, W. K. Coblentz, K. P. Coffey, J. E. Turner, D. A. Scarbrough, J. A. Jennings, and M. D. Richardson Ruminal in situ disappearance kinetics of nitrogen and neutral detergent insoluble nitrogen from common crabgrass forages sampled on seven dates in northern Arkansas J Anim Sci, March 1, 2006; 84(3): 669 - 677. [Abstract] [Full Text] [PDF]

				J. D. Arthington and W. F. Brown Estimation of feeding value of four tropical forage species at two stages of maturity J Anim Sci, July 1, 2005; 83(7): 1726 - 1731. [Abstract] [Full Text] [PDF]

				R. K. Ogden, W. K. Coblentz, K. P. Coffey, J. E. Turner, D. A. Scarbrough, J. A. Jennings, and M. D. Richardson Ruminal in situ disappearance kinetics of dry matter and fiber in growing steers for common crabgrass forages sampled on seven dates in northern Arkansas J Anim Sci, May 1, 2005; 83(5): 1142 - 1152. [Abstract] [Full Text] [PDF]

				A. Adeli, J. J. Varco, K. R. Sistani, and D. E. Rowe Effects of Swine Lagoon Effluent Relative to Commercial Fertilizer Applications on Warm-Season Forage Nutritive Value Agron. J., March 1, 2005; 97(2): 408 - 417. [Abstract] [Full Text] [PDF]

				H. K. Pant, M. B. Adjei, J. M. S. Scholberg, C. G. Chambliss, and J. E. Rechcigl Forage Production and Phosphorus Phytoremediation in Manure-Impacted Soils Agron. J., November 1, 2004; 96(6): 1780 - 1786. [Abstract] [Full Text] [PDF]

				A. H. Garay, L. E. Sollenberger, D. C. McDonald, G. J. Ruegsegger, R. S. Kalmbacher, and P. Mislevy Nitrogen Fertilization and Stocking Rate Affect Stargrass Pasture and Cattle Performance Crop Sci., July 1, 2004; 44(4): 1348 - 1354. [Abstract] [Full Text] [PDF]

				K. R. Woodard, E. C. French, L. A. Sweat, D. A. Graetz, L. E. Sollenberger, B. Macoon, K. M. Portier, S. J. Rymph, B. L. Wade, G. M. Prine, et al. Nitrogen Removal and Nitrate Leaching for Two Perennial, Sod-Based Forage Systems Receiving Dairy Effluent J. Environ. Qual., May 1, 2003; 32(3): 996 - 1007. [Abstract] [Full Text] [PDF]

				Y. C. Newman, L. E. Sollenberger, W. E. Kunkle, and D. B. Bates Crude Protein Fractionation and Degradation Parameters of Limpograss Herbage Agron. J., November 1, 2002; 94(6): 1381 - 1386. [Abstract] [Full Text] [PDF]