A study of 15N transfer between legumes and grasses Florence Paynel, Fabien Lesuffleur, Jacques Bigot, Sylvain Diquélou and Jean-Bernard Cliquet Agron. Sustain. Dev., 28 2 (2008) 281-290 Published online: 22 March 2008 DOI: 10.1051/agro:2007061