02328naa a2200253 a 450000100080000000500110000800800410001902200140006010000160007424501510009026000090024152015870025065000130183765000140185065300190186465300260188370000200190970000160192970000170194570000160196270000170197870000160199577300630201121308462021-10-05       2021    bl uuuu     u00u1 u    #d  a1385-13141 aPEREIRA, W.  aNitrogen acquisition and 15N-fertiliser recovery efficiency of sugarcane cultivar RB92579 inoculated with five diazotrophs.h[electronic resource]  c2021  aWe aimed to evaluate N acquisition and 15N-fertiliser recovery efficiency of sugarcane as a function of N fertilisation and inoculation with plant growth-promoting diazotrophic bacteria (PGPDB) during the first crop season. A field experiment was performed with a randomized complete block design consisting of four replications and four treatments: control without N and without inoculation; control without N but with inoculation of a mixture of five strains of diazotrophic bacteria; N treatment (50 kg ha−1 N-urea) without inoculation; and N treatment with inoculation. Over seven harvests, we evaluated crop growth, biomass accumulation, N content, and N recovery using 15N-urea (excess of 1.5% atoms 15N). In addition, the contribution of biological N fixation (BNF) was measured using the 15N natural abundance technique in the plots without N fertiliser application. Inoculation with the mixture of five PGPDB strains increased the yield by 15% and N content in the shoots by 18% over the cycle. The average contribution of N fertiliser in plant N nutrition was 13%; other sources accounted for a large part of N in the shoots. Plants received N via BNF in 31% (average) of the treatments during the plant cycle; however, inoculation did not interfere with this process. The recovery efficiency of 15N-fertiliser was 50% in this first cycle with no differences among inoculation treatments. Nitrogen fertiliser applied to sugarcane resulted in a low impact on N accumulation, and a single application of an inoculant improved plant growth by mechanisms other than BNF.  aIsotopes  aSugarcane  a15N fertiliser  aDiazotrophic bacteria1 aOLIVEIRA, R. P.1 aPEREIRA, A.1 aSOUZA, J. S.1 aNIVALDO, S.1 aURQUIAGA, S.1 aREIS, V. M.  tNutrient Cycling in Agroecosystemsgv. 119, p.37-50, 2021.