02236naa a2200253 a 450000100080000000500110000800800410001910000190006024501400007926000090021950001570022852013180038565000170170365000210172065300310174165300290177265300270180170000210182870000170184970000170186670000190188370000200190277300600192221223272020-05-14       2020    bl uuuu     u00u1 u    #d1 aAGUIRRE, P. F.  aBiological nitrogen fixation and urea-N recovery in 'Coastcross-1' pasture treated with Azospirillum brasilense.h[electronic resource]  c2020  aTítulo em português: Fixação biológica de nitrogênio e recuperação de N-ureia em pastagem de 'Coastcross-1' tratada com Azospirillum brasilense.  aThe objective of this work was to quantify the inoculation effect of Azospirillum brasilense (Ab-V5 and Ab-V6 strains) on the forage yield, biological nitrogen fixation (BNF), and urea-15N recovery of the forage grass 'Coastcross-1'. The experiment was carried out in a 2 (with or without inoculation) × 2 (without N fertilizer and with 100 kg ha-1 N per year as urea) × 7 (cuts) factorial arrangement. The natural 15N abundance method was used to determine BNF; to determine urea-N recovery, 15N-labeled urea was applied in microplots. Forage yield was higher in grasses subjected to inoculation, with 7.4 Mg ha-1 dry matter per year, for the treatment without N fertilizer, and 8.0 Mg ha-1 dry matter per year for the treatment with 100 kg ha-1 N per year, respectively, which shows an additive effect of inoculation and N fertilization. The contribution of BNF was 23.0 and 53.8 kg ha-1 per year for the unfertilized treatment, both in uninoculated and inoculated plants, respectively. Urea-15N recovery was 13.7 and 16.5 kg ha-1 per year for uninoculated and inoculated treatments, respectively, corresponding to 13.7 and 16.5% of the urea-N applied. Inoculation with A. brasilense increases forage yield and the contribution of BNF to grass nutrition with N, as well as urea-N recovery by the forage grass.  aForage yield  aCynodon Dactylon  aAbundância natural de 15N  aNatural abundance of 15N  aProdução de forragem1 aGIACOMINI, S. J.1 aOLIVO, C. J.1 aBRATZ, V. F.1 aQUATRIN, M. P.1 aSCHAEFER, G. L.  tPesquisa Agropecuária Brasileiragv. 55, e01242, 2020.