Lignocellulosic crops in rotation with food crops

Enhancing agricultural multifunctionality is viable in a multi-purpose crops intensification scenario. The cultivation of a sequence of food and energy crop has the potential to strengthen the crop rotation effect without reducing food land. Annual lignocellulosic crops for advanced biofuel could be introduced alongside conventional crops during the periods of the year on which the latter ones are not cultivated thus to increase the period of utilization of the land unit (increased LER). In this study a preliminary assessment of the effect of four dedicated lignocellulosic crops (sunn hemp, fiber sorghum, kenaf, and hemp) on a subsequent cereal is given in terms of biomass yields. The dedicated lignocellulosic crops have been tested within conventional sequential crop rotations (maize - wheat rotation). Preliminary results indicate that biomass sorghum and kenaf produced the highest and lowest yields, respectively. Whereas industrial hemp and sunn hemp were intermediate to such extremes. Kenaf negatively affected the yield of the subsequent wheat straw that decreased compared to the industrial hemp and sunn hemp by 15%. Whereas the production of wheat straw after biomass sorghum and conventional rotation was intermediate. This preliminary finding indicates that depending on the species characteristics it would be possible to introduce dedicated lignocellulosic crops within conventional crop rotations. Moreover, the biomass characterization highlighted whether the investigated feedstocks were suitable to thermo/biochemical conversion. Further investigations, however, are required to assess the overall systems feasibility and sustainability.