State-of-the-art of the Jatropha curcas productive chain: from sowing to biodiesel and by-products

In the forthcoming years, 1-2 million hectares of Jatropha curcas L. are expected to be annually planted, reaching 12.8 million hectares worldwide by 2015. This considerable expansion is due to its products and byproducts multiple uses and its amazing adaptability. J. curcas oil extracted by seeds is a promising renewable feedstock for biodiesel production and, together with the oil extraction by-products, it can be used as cooking/lighting fuel, bio-pesticide, organic fertilizer, combustible fuel, and for soap making. The capability to grow on poor quality soils not suitable for food crop makes J. curcas a possible solution of all the controversies related to biodiesel production. Furthermore, J. curcas contributes to mitigate environmental problems, such as marginal land or abandoned farmland reclamation. Nevertheless, J. curcas is not a “miracle tree”: i) the full potential of J. curcas is far from being achieved and its talents are still to be supported by scientific evidences; ii) J. curcas capabilities are not easily exploitable and applicable simultaneously; iii) its use is controversial and potentially unsustainable due to the current knowledge gaps about the impacts and potentials of J. curcas plantations. The aims of this review are to detail each phase of J. curcas productive chain from sowing to biodiesel and by-products, in order to logically organize the knowledge around J. curcas system, and to compare potentialities and criticalities of J. curcas, highlighting the agronomical, management, and environmental issues which should be still investigated.