Evaluation of nitrogen fixtation in horsebean (Vicia faba minor Beck) as affected by sulphur fertilization in a hilly area of Basilicata region (Itay).

Sulphur is one of the essential nutrients for plants and it is a fundamental element in the nitrogenase enzymatic complex, being part as a basic constituent of the metallic cofactors affecting electron transfer in the nitrogen fixation process (Brady and Weil, 1996). The need of sulphur to optimise nitrogen use and improve yield and yield quality is increasing and it will be an important factor in the next future (McGrath et al., 2002). Soil sulphur content impoverishment was observed due mainly to environmental policies aimed to reduce gas pollutants in the atmosphere and will became a phenomenon of great importance (Scherer, 2001).