Lima Filho, S.A. de and Neptune, A.M.L. 1982. Effects of N-NO-3 and N-NH+4 on the fresh and dry matter, on the nitrogen concentrations and on the nitrate reductase activity in Vigna unguiculata (L.) Walp . Anais da Escola Superior de Agricultura Luiz de Queiroz. 39, 2 (Jan. 1982), 1089–1114. DOI:https://doi.org/10.1590/S0071-12761982000200025.