00546naa a2200169 a 450000100080000000500110000800800410001910000170006024501740007726000090025165000260026065000120028665300080029865300120030670000180031877300400033616084521995-06-27       1987    bl ---       0--  u    #d1 aURQUIAGA, S.  aTheoretical considerations in the comparison of total nitrogen difference and 15N isotope dilution estimates of the contribution of nitrogen fixation to plant nutrition.  c1987  aDiluição Isotópica  aMétodo  a15N  aUAPNPBS1 aBODDEY, R. M.  tPlant Soilgv.102, p.291-294, 1987.