The climatic, energetic and political context promotes the development of bioenergies. However we have a lack of knowledge to find out the best energy crops, depending on the soil, the climate and the end­use. This work aimed at studying the adaptation and the biomass and biofuel yield, of several energy crops grown in France in different soil and climate conditions. The biomass yields were very variable between the different experimental sites and no differences were observed on the median biomass yield between crops. Moreover, there was no evidence of a highly productive crop in all the conditions of soil and climate. Because of little differences of the lower heating value between crops, no differences were observed on the primary energy yield. The ethanol yield per hectare was higher for miscanthus, switchgrass and fiber sorghum because of higher cellulose content in these crops. The nitrogen removed at harvest by miscanthus and switchgrass were significantly lower than the other crops witch could lead to reduced fertilizer­N requirements. Further research are needed to clarify the effect of limiting factors on the biomass yield of the different energy crops and to consider other parameters such as the environmental impacts to give rules to choose the most suitable crop in a given region.

Proceedings of the 18th European Biomass Conference and Exhibition, 3-7 May 2010, Lyon, France, pp. 269-272