The aim of this paper is to develop such an analysis for agriculture in France, which offers a useful case study since the crops grown in France are highly diverse and correspond to a wide range of pesticide use intensities. The approach consists in building an artificial index of pesticide use at the national level, one in which variations over time depend solely on land use changes. The purpose of this index is not to provide an accurate description of overall pesticide use variations over time, but to reveal the underlying portion of these variations which results directly from changes in landuse. This index of artificial pesticide use is calculated each year for the period 1989–2013, during which different types of land use changes occurred in connection with changes in the political and socioeconomic context. In particular, the European Common Agricultural Policy (CAP) was substantially revised in 1992, and again in 1999, 2003 and 2009. In addition to this historical analysis,aprospective approach is outlined by comparing the values of the index associated with three contrasting land use scenarios corresponding to different options of agri-environmental policy. Lastly, a focussed analysis is made of the 2009–2013 period, corresponding to the five first years of implementation of the Ecophyto Plan. For this period, an official indicator of pesticide consumption, defined on the basis of annual pesticide sales, is available. Comparing variations over time of this indicator and our index allows us to evaluate to what extent land use changes worked against, or on the contrary reinforced, the general objective of the Ecophyto Plan. This opportunity to compare simulated and observed data is another reason France makes an interesting case study.