Management of nitrogen fertilization of winter wheat and potato crops using the chlorophyll meter for crop nitrogen status assessment Jean-Paul Denuit, Marguerite Olivier, Marie-Julie Goffaux, Jean-Luc Herman, Jean-Pierre Goffart, Jean-Pierre Destain and Marc FrankinetAgronomie, 22 7-8 (2002) 847-853DOI: https://doi.org/10.1051/agro:2002065