Spatial distribution of weed diversity within a cereal field J. Izquierdo, J.M. Blanco-Moreno, L. Chamorro, J.L. González-Andújar and F.X. Sans Agron. Sustain. Dev., 29 3 (2009) 491-496 Published online: 01 July 2009 DOI: 10.1051/agro/2009009