The cost of mitigating greenhouse gas emissions from crop fertilization.

Summary The objective of this thesis is to estimate the cost of greenhouse gas (GHG) emission mitigation measures related to crop fertilization, which represents 38% and 44% of agricultural GHG emissions in Europe and France, respectively. The study of the cost and mitigation potential is carried out on two key measures in the mitigation of emissions, namely the establishment of nitrogen fixing plants (i.e. legumes) and the reduction of fertilization per hectare. The mitigation potential of legumes is studied by simulating their increase in French crop rotations and then on the scale of crop rotations lasting up to six years in five European regions. The results show that significant emission reductions are possible, while increasing farmers' profits. The role of risk aversion is also investigated regarding the reduction of crop fertilization per hectare. We analytically show the conditions leading to an over-application of fertilizer per hectare allowing risk averse farmers to minimize the risk of yield loss. Numerical simulations performed specifically on risk averse farmers demonstrate that emission mitigation insurance can potentially trigger significant reductions in greenhouse gas emissions.