00919naa a2200169 a 450000100080000000500110000800800410001902200140006010000200007424500740009426000090016852004550017765300400063270000190067270000180069177300400070916303642018-04-20       2008    bl ---       0--  u    #d  a1435-86031 aHERRIDGE, D. F.  aGlobal inputs of biological nitrogen fixation in agricultural systems  c2008  aIn this paper we review and update long-standing and more recent estimates of biological N2 fixation for the different agricultural systems, including the extensive, uncultivated tropical savannas used for grazing. Our methodology was to combine data on the areas and yields of legumes and cereals from the Food and Agriculture Organization (FAO) database on world agricultural production (FAOSTAT) with published and unpublished data on N2 fixation.  aFixação biológica de nitrogênio1 aPEOPLES, M. B.1 aBODDEY, R. M.  tPlant and Soilgv.311, p.1-18, 2008