IMPACT4SOIL OpenAire Bielefeld Academic Search Engine (BASE) UnpayWall Crossref Microsoft Academic Graph Europe PubMed Central Philosophical Transactions of the Royal Society B: Biological Sciences Open Access 2012-03-26 <p> In earlier work, we compared the amount of newly fixed nitrogen (N, as synthetic fertilizer and biologically fixed N) entering agricultural systems globally to the total emission of nitrous oxide (N 2 O). We obtained an N 2 O emission factor (EF) of 3￢ﾀﾓ5%, and applied it to biofuel production. For ￢ﾀﾘfirst-generation￢ﾀﾙ biofuels, e.g. biodiesel from rapeseed and bioethanol from corn (maize), that require N fertilizer, N 2 O from biofuel production could cause (depending on N uptake efficiency) as much or more global warming as that avoided by replacement of fossil fuel by the biofuel. Our subsequent calculations in a follow-up paper, using published life cycle analysis (LCA) models, led to broadly similar conclusions. The N 2 O EF applies to agricultural crops in general, not just to biofuel crops, and has made possible a top-down estimate of global emissions from agriculture. Independent modelling by another group using bottom-up IPCC inventory methodology has shown good agreement at the global scale with our top-down estimate. Work by Davidson showed that the rate of accumulation of N 2 O in the atmosphere in the late nineteenth and twentieth centuries was greater than that predicted from agricultural inputs limited to fertilizer N and biologically fixed N (Davidson, E. A. 2009 Nat. Geosci . 2 , 659￢ﾀﾓ662.). However, by also including soil organic N mineralized following land-use change and NO x deposited from the atmosphere in our estimates of the reactive N entering the agricultural cycle, we have now obtained a good fit between the observed atmospheric N 2 O concentrations from 1860 to 2000 and those calculated on the basis of a 4 per cent EF for the reactive N. </p> 2. Zero hunger Air Pollutants 330 Climate Nitrous Oxide Agriculture 15. Life on land Nitrification 01 natural sciences 7. Clean energy 630 Soil 13. Climate action Biofuels Denitrification 0105 earth and related environmental sciences Wilfried Winiwarter, Wilfried Winiwarter, Keith Smith, Paul J. Crutzen, Arvin R. Mosier, 2012-05-05 journalpaper <p> In earlier work, we compared the amount of newly fixed nitrogen (N, as synthetic fertilizer and biologically fixed N) entering agricultural systems globally to the total emission of nitrous oxide (N 2 O). We obtained an N 2 O emission factor (EF) of 3￢ﾀﾓ5%, and applied it to biofuel production. For ￢ﾀﾘfirst-generation￢ﾀﾙ biofuels, e.g. biodiesel from rapeseed and bioethanol from corn (maize), that require N fertilizer, N 2 O from biofuel production could cause (depending on N uptake efficiency) as much or more global warming as that avoided by replacement of fossil fuel by the biofuel. Our subsequent calculations in a follow-up paper, using published life cycle analysis (LCA) models, led to broadly similar conclusions. The N 2 O EF applies to agricultural crops in general, not just to biofuel crops, and has made possible a top-down estimate of global emissions from agriculture. Independent modelling by another group using bottom-up IPCC inventory methodology has shown good agreement at the global scale with our top-down estimate. Work by Davidson showed that the rate of accumulation of N 2 O in the atmosphere in the late nineteenth and twentieth centuries was greater than that predicted from agricultural inputs limited to fertilizer N and biologically fixed N (Davidson, E. A. 2009 Nat. Geosci . 2 , 659￢ﾀﾓ662.). However, by also including soil organic N mineralized following land-use change and NO x deposited from the atmosphere in our estimates of the reactive N entering the agricultural cycle, we have now obtained a good fit between the observed atmospheric N 2 O concentrations from 1860 to 2000 and those calculated on the basis of a 4 per cent EF for the reactive N. </p> The Role Of N2o Derived From Crop-Based Biofuels, And From Agriculture In General, In Earth'S Climate 10.1098/rstb.2011.0313 https://doi.org/10.1098/rstb.2011.0313