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Reducing the use of nitrogen fertilizers: how and what potential impact on N2O emissions from French
agriculture?
Catherine Hénault, Laure Bamière, Sylvain Pellerin, Marie-Helene Jeuffroy, Sylvie Recous
To cite this version:
Catherine Hénault, Laure Bamière, Sylvain Pellerin, Marie-Helene Jeuffroy, Sylvie Recous. Reduc- ing the use of nitrogen fertilizers: how and what potential impact on N2O emissions from French agriculture?. Climate SMART Agriculture 2015 - Global science conference - Towards Climate smart Solutions, Mar 2015, Montpellier, France. �hal-01173064�
Reducing the use of nitrogen fertilizers: how and what potential impact on N2O emissions from French
agriculture?
Key words : agriculture, greenhouse gases, legumes, organic fertilizers, mitigation, nitrogen fertilization
Hénault C.(1), Bamière L.(2), Pellerin S. (3), Jeuffroy M.H.(4), Recous S.(5)
1INRA, UR Sciences du Sol, 45075 Orléans, France
2INRA, UMR Eco-Pub, 78850 Thiverval-Grignon, France 3INRA, UMR ISPA, 33883 Villenave d’Ornon,France
4INRA, UMR Agronomie INRA-AgroParisTech, 78850 Thiverval-Grignon, France
5INRA, UMR Fractionnement des AgroRessources et Environnement; 51100 Reims, France
1. Introduction
3. Results
2. Materials and Methods
4. Conclusions
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Different measures to reduce the use of fertilisers were tested (table 1)
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The information on current fertiliser application practices is derived from the 2006 “Cropping practices” survey
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The emissions abatement results from the effect of the different measures on the total mineral nitrogen applied, losses due to leaching and volatilisation ouside the field, upstream emissions related to the production and transport of synthetic fertilisers.
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Two methods were used : a calculation using current national inventory rules, based on 1996 IPCC recommendations (“CITEPA method”), and an “expert” calculation, based on French published observations (figure 2), IPCC 2006 emission factor values, specific coefficients from the scientific literature, adapted to the proposed measures
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The unitary cost for the farmer was assessed by taking into account any specific equipment or product required, saving of synthetic nitrogen fertiliser and of technical operations
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The impact at the national scale was assessed by taking into account the maximum technical potential applicability (MTPA) and an adoption scenario
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An abatment potential in 2030 was then calculated (table 2)
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We observed a real potential of N2O emission abatement, (around 200-300 kgCO2e/ha/y) by reducing the use of Nitrogen fertiliser without affecting yields. These values are close to those estimated in similar studies conducted abroad.
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Except of the measure involving the use of a nitrification inhibitor, the other measures are « win-win » since reducing fertiliser applications both reduce N2O emissions and costs for farmers.
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Assuming the different measures could be additive, the averall abatement in 2030 could be of 6.1 MtCO2e (« expert » calculation, excluded induced emissions)
With the financial support of
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In France, N2O emissions by cultivated soils contribute to around 50% of agricultural greenhouse gas emissions. These emissions are particularly associated with the use of synthetic nitrogen fertilizers both through direct and indirect emissions (figure 1).
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There is now a consensus with respect to the significance of excess nitrogen in cultivated systems in France, the low overall efficiency of the nitrogen supplied to the soil by synthetic mineral fertilisers, and finally, the potential for good farmer practices to improve the situation.
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The aim of this study is to evaluate the possiblities of reducing N2O emissions by simultaneously reducing synthetic fertiliser doses and emissions per unit of nitrogen supplied, without affected yields
3,7 Mha
Figure 1 : Processes of N2O emissions
Figure 2 : Part of the definition of the « expert function »
Table 1
Table 2
