00558naa a2200193 a 450000100080000000500110000800800410001910000200006024501250008026000090020565000260021465000120024065300080025265300230026065300080028370000150029170000200030677300380032616199791995-06-27       1992    bl ---       0--  u    #d1 aDOUGHTON, J. A.  aAn indirect method for estimating 15N isotope fractionation during nitrogen fixation by a legume under field conditions.  c1992  aDiluição Isotópica  aMétodo  a15N  aABUNDANCIA NATURAL  aFBN1 aVALLIS, I.1 aSAFFIGNA, P. G.  tPlant Soilgv.144, p.23-29, 1992.