SWARD STRUCTURE AND NUTRITIVE VALUE OF UROCHLOA RUZIZIENSIS UNDER NITROGEN AND POTASSIUM FERTILISATION

Authors

  • Karla Rodrigues de Lima Science center and agricultural technology, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ.
  • Carlos Augusto Brandão de Carvalho Department of animal nutrition and pasture, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ.
  • Flavio Henrique Vidal Azevedo Science center and agricultural technology, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ.
  • Pedro Antonio Muninz Malafaia Department of animal nutrition and pasture, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ.

DOI:

https://doi.org/10.1590/1983-21252017v30n124rc

Keywords:

Crude protein. Forage mass. Lignin. Neutral detergent fibre. Sward height.

Abstract

This study aimed to assess the effect of nitrogen (N) and potassium (K) fertilisation on the forage accumulation and nutritive value of Urochloa ruziziensis during the summer of 2010/2011 and autumn, winter, spring and summer of 2011/2012. A complete randomised block design with four treatments (0, 120, 240 and 360 kg ha-1 year-1 N and K2O) and five replicates were used. The data were analysed under the PROC MIXED of SAS®. The following variables were evaluated: sward height; forage mass; forage bulk density; percentages of leaf blade dry matter, stem dry matter, and dead material dry matter; leaf blade:stem ratio; contents of dry matter and crude protein; in vitro digestibility of dry matter; neutral detergent fibre content; and lignin content of Urochloa ruziziensis. There was an interaction between the N and K levels of fertilisation and the season for all variables. In addition, there was a positive linear effect of the N and K levels of fertilisation on the forage accumulation rate, the crude protein content and the in vitro digestibility of dry matter and a negative linear effect these levels on the neutral detergent fibre and lignin contents during the spring and summer of 2011/2012. N and K fertilisation and the climate changes characteristic of each season jointly affected the accumulation and nutritive value of Urochloa ruziziensis. N and K fertilisation up to 360 kg ha-1 year-1 improved the forage accumulation and nutritive value of Urochloa ruziziensis.

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Published

02-12-2016

Issue

Section

Zootechnics