Nitrogen and Grazing Affect Napier Grass Leaf Litter Biomass and Decomposition Academic Article uri icon

abstract

  • © 2017 by the American Society of Agronomy. Stocking rate (SR) and N fertilization are important management practices that may alter nutrient cycling. We tested three SR [2, 3.9, and 5.8 animal units (AU) ha-1; 1 AU = 450 kg BW] and three N rates (0, 150, and 300 kg N ha-1yr-1) on litter mass, chemical composition, and decomposition in a napier grass (Pennisetum purpureum Schum.) pasture. Fertilizer rate did not change (P = 0.4658) litter accumulation but decomposition after 254 d was greatest (P ≤ 0.05) at the greatest management intensity. Litter mass was affected by a year × month interaction (P ≤ 0.01), but in general the greatest litter mass occurred (P ≤ 0.05) at the end of the growing season, and carried over to beginning of the next growing season. There was a SR × year interaction for litter mass. At 3.9 and 5.8 AU ha-1, litter mass was greater in 2009 than in 2010. Visual observation indicated that in 2010 at the 3.9 and 5.8 AU ha-1> SR, the napier grass pasture was degrading, generating less biomass and consequently less litter than in 2009. In general, litter C/N ratio was above 30. There was no effect of SR (P = 0.2684) or SR interaction with year (P = 0.1558) on litter N concentration, with an average of 14 g N kg-1. Our results indicated that napier grass management affect litter mass and C/N ratio. This has implications for litter decomposition and nutrient dynamics in these pastures.

altmetric score

  • 1

author list (cited authors)

  • Apolinário, V., Dubeux, J., Lira, M. A., Mello, A., Santos, M., Muir, J. P., & de Freitas, E. V.

citation count

  • 0

publication date

  • November 2017