Innovative agronomic solutions to rescue marginal soil and to produce sustainable biodiesel

Biodiesel is a non-toxic, biodegradable, environmentally friendly alternative diesel fuel, produced from food-grade vegetable oils through a transesterification reaction with methanol and an alkaline catalyst. In this study the use of alternative oil crops like Brassica spp. (B. carinata, B. juncea) and Nicotiana tabacum for biodiesel production is investigated. Using a method based on the life cycle thinking approach we aim to assess the sustainability of biodiesel production from these two innovative cultivations in crop rotation. B. carinata has high yield both in adverse conditions and under low cropping system. The aim is to exploit Brassica spp. to get better agronomic performances in areas characterized by unfavourable environmental conditions for other cultivations. Moreover Brassica spp. tissues contain high concentrations of glucosinolates that can be hydrolyzed to isothiocyanate by the plant enzymes under conditions of physical injury. Biofumigation effect of isothiocyanate released from soil-incorporated Brassica spp. tissues is known to reduce soil plant pathogens and it could be an alternative method to chemical plant disease control measures. This is useful for Nicotiana tabacum, susceptible to nematode infection, being an interesting alternative oil seed cultivation due to its high yield patent selections. Taking advantage of all these Brassica spp. and Nicotiana tabacum characteristics it could be possible not only to produce high yields of oil seeds but also to reclaim nematode infected fields. This study is part of a wider project on biodiesel (project SUSBIOFUEL), which is comprehensive of the optimization of the chemical reaction from oil to biodiesel. Using not refined or waste oils as a feedstock represents a convenient way to lower biodiesel production costs. One of the main problems using this type of low-cost feedstock lies in its high content of FFA (Free Fatty Acids), leading to the formation of soaps during the transesterification reaction. The project SUSBIOFUEL is funded by the Italian Ministry of Agriculture (MIPAAF).