How Corn Is Cultivated in France? a Cropping Systems Typology to Support Public Decision Making on Genetically Modified Cultivars.

EU member-states have to consider social and economic dimensions, to support their decisions about genetically modified organism (GMO). To assess the impacts of authorizing or not GMO’s cultivation, a baseline is required. GM cultivars are not authorized in France even for corn (Zea mays L.) which is the second crop in France in terms of acreage. Thus, a typology of current cropping systems has been carried out for this crop to identify the potential agronomic interest of GM cultivars.

This typology is based on a 5000-plots survey from public statistics and adapted from a method commonly used to develop farming systems typologies. This method combines factor analysis and hierarchical clustering. We performed this analysis, in a first time to classify corn crop management plans (CMP), and in a second time, to classify crop sequences in which corn occurs. We called a cropping system (CS) the combination of a given CMP with a given crop sequence.

Doing this way we first distinguished between four CMP types and described their characteristics (soil tillage, sowing practices, fertilization, pest management, irrigation…). Second, we distinguished between five crop sequences types (e.g. corn monocropping, corn rotating with straw cereals, crop sequences including meadow…). Among the 20 possible combinations, we finally identified nine dominant CS, gathering 75% of the sample. These results formed a basis to assess GM cultivars adoption. Indeed, it contributed to investigate GM cultivars adoption potential (e.g., as two CS concentrate plots with corn borer insecticide, Bt-cultivars adoption seems not to be investigated for the other CS). Then, it could be use as a baseline for assessing scenarios of GM-cultivars adoption, with relevant economic and social indicators calculation. This approach could be applied for any crops, to assess impacts of any cropping innovation.