01952naa a2200241 a 450000100080000000500110000800800410001902200140006002400500007410000190012424500880014326000090023152012050024065000250144565000160147065000220148665000110150865300220151970000200154170000190156170000230158077301070160320427552017-03-03       2016    bl uuuu     u00u1 u    #d  a1807-19297 a10.1590/1807-1929/agriambi.v20n5p401-4072DOI1 aLIMA, J. E. S.  aUrochloa ruziziensis responses to sources and doses of urea.h[electronic resource]  c2016  aThe use of products that promote reduction of nitrogen (N) losses from the urea fertilizer can contribute to increasing its use efficiency in forage grasses. This study aimed to evaluate the effects of N sources and doses on the growth of Urochloa ruziziensis. The experiment was carried out in the growing season of 2007/2008 in Santo Antônio de Goiás-GO, in a Brazilian Oxisol. A completely randomized block was used, with four replicates in a factorial scheme, corresponding to two N sources (conventional urea and urea with urease inhibitor) and five N doses (0, 50, 100, 200 and 300 kg ha-1), divided into equal applications in five periods (Nov 14 to Dec 13, Dec 14 to Jan 12, Jan 13 to Feb 11 ? rainy season, Mar 24 to Apr 22 and Jul 10 to Aug 08 ? dry season). The effects of the treatments were evaluated for: shoot dry matter, tiller density, total N content in the leaves and relative chlorophyll content. N fertilizer sources did not affect the evaluated variables; however, N fertilization allowed linear increases in all variables with higher values during the rainy period. The relative chlorophyll content in U. ruziziensis had positive correlation with its dry matter productivity.  aUrochloa ruziziensis  aNitrogênio  aPlanta forrageira  aUréia  aTeor de clorofila1 aNASCENTE, A. S.1 aLEANDRO, W. M.1 aSILVEIRA, P. M. da  tRevista Brasileira de Engenharia Agrícola e Ambiental, Campina Grandegv. 20, n. 5, p. 401-407, 2016.